For form, a string specifying the name of the window that responses go to after a form has been submitted. For link, a string specifying the name of the window that displays the content of a clicked hypertext link.

语法

1. formName.target
2. links[index].target

formName is either the name of a form or an element in the forms array.
index is an integer representing a link object.

Property of

form, link

描述

The target property initially reflects the TARGET attribute of the <FORM> and <A> tags; however, setting target overrides these attributes.

The target property cannot be assigned the value of a JavaScript expression or variable.

You can set the target property at any time.

Certain values of the target property may require specific values for other form properties. See RFC 1867 for more information.

例子

The following example specifies that responses to the musicInfo form are displayed in the "msgWindow" window:

document.musicInfo.target="msgWindow"

相关

For form:

A text input field on an htm form. A text field lets the user enter a word, phrase, or series of numbers.

语法

To define a text object, use standard htm 语法 with the addition of the onBlur, on Change, onFocus, and onSelect event handlers:

<INPUT
   TYPE="text"
   NAME="textName"
   VALUE="textValue"
   SIZE=integer
   [onBlur="handlerText"]
   [onChange="handlerText"]
   [onFocus="handlerText"]
   [onSelect="handlerText"]>

To use a text object's properties and methods:

1. textName.propertyName
2. textName.methodName(parameters)
3. formName.elements[index].propertyName
4. formName.elements[index].methodName(parameters)

Property of

描述

A text object on a form looks as follows:

A text object is a form element and must be defined within a <FORM> tag.

text objects can be updated (redrawn) dynamically by setting the value property (this.value).

Properties

Methods

Event handlers

例子

Example 1. The following example creates a text object that is 25 characters long. The text field appears immediately to the right of the words "Last name:". The text field is blank when the form loads.

Example 2. The following example creates two text objects on a form. Each object has a default value. The city object has an onFocus event handler that selects all the text in the field when the user tabs to that field. The state object has an onChange event handler that forces the value to upper case.

相关 the 例子 for the onBlur, onChange, onFocus, and onSelect event handlers.

相关

A string specifying the text that follows an <OPTION> tag in a select object.

语法

selectName.options[index].text

selectName is either the value of the NAME attribute of a select object or an element in the elements array.
index is an integer representing an option in a select object.

Property of

options array

描述

The text property initially reflects the text that follows an <OPTION> tag in a select object.

You can set the text property at any time; however, the following effects result:

Be careful if you change the text property. If you evaluate the property after you change it, the property contains the new value, not the value that is displayed onscreen.

例子

In the following example, the getChoice() function returns the value of the text property for the selected option. The for loop evaluates every option in the musicType select object. The if statement finds the option that is selected.

function getChoice() {
   for (var i = 0; i < document.musicForm.musicType.length; i++) {
      if (document.musicForm.musicType.options[i].selected == true) {
         return document.musicForm.musicType.options[i].text
      }
   }
   return null
}

<SELECT NAME="musicType">
   <OPTION SELECTED> R&B
   <OPTION> Jazz
   <OPTION> Blues
   <OPTION> New Age
</SELECT>

A multiline input field on an htm form. A textarea field lets the user enter words, phrases, or numbers.

语法

To define a text area, use standard htm 语法 with the addition of the onBlur, onChange, onFocus, and onSelect event handlers:

<TEXTAREA
   NAME="textareaName"
   ROWS="integer"
   COLS="integer"
   WRAP="off|virtual|physical"
   [onBlur="handlerText"]
   [onChange="handlerText"]
   [onFocus="handlerText"]
   [onSelect="handlerText"]>
   textToDisplay
</TEXTAREA>

The WRAP attribute controls word wrapping inside the TEXTAREA. The value "off" is default and lines are sent exactly as typed. The value "virtual" wraps in the display but are sent exactly as typed. The value "physical" wraps in the display and sends new-lines at the wrap points as if new-lines had been entered.

To use a textarea object's properties and methods:

1. textareaName.propertyName
2. textareaName.methodName(parameters)
3. formName.elements[index].propertyName
4. formName.elements[index].methodName(parameters)

Property of

描述

A textarea object on a form looks as follows:

A textarea object is a form element and must be defined within a <FORM> tag.

textarea objects can be updated (redrawn) dynamically by setting the value property (this.value).

To begin a new line in a textarea object, you can use a newline character. This character varies from platform to platform: Unix is \n, Windows is \r\n, and Macintosh is \n. One way to enter a newline character programatically is to test the appVersion property to determine the current platform and set the newline character accordingly. See the appVersion property for an example.

Properties

Methods

Event handlers

例子

The following example creates a textarea object that is 6 rows long and 55 columns wide. The textarea field appears immediately below the word "描述:". When the form loads, the textarea object contains several lines of data, including one blank line.

相关 the 例子 for the onBlur, onChange, onFocus, and onSelect event handlers.

相关

A string representing the title of a document.

语法

document.title

Property of

document

描述

The title property is a reflection of the value specified within the <TITLE> and </TITLE> tags. If a document does not have a title, the title property is null.

title is a read-only property.

例子

In the following example, the value of the title property is assigned to a variable called docTitle:

var newWindow = window.open("http://www.netscape.com")
var docTitle = newWindow.document.title

Converts a date to a string, using the Internet GMT conventions.

语法

dateObjectName.toGMTString()

dateObjectName is either the name of a date object or a property of an existing object.

用法

Date

描述

The exact format of the value returned by toGMTString varies according to the platform.

例子

today.toGMTString()

In this example, the toGMTString method converts the date to GMT (UTC) using the operating system's time zone offset and returns a string value that is similar to the following form. The exact format depends on the platform.

Mon, 18 Dec 1995 17:28:35 GMT

相关

Converts a date to a string, using the current locale's conventions.

语法

dateObjectName.toLocaleString()

dateObjectName is either the name of a date object or a property of an existing object.

用法

Date

描述

例子

today.toLocaleString()

In this example, toLocaleString returns a string value that is similar to the following form. The exact format depends on the platform.

12/18/95 17:28:35

相关

Returns the calling string value converted to lower case.

语法

stringName.toLowerCase()

stringName is any string or a property of an existing object.

用法

string

描述

The toLowerCase method returns the value of stringName converted to lower case. toLowerCase does not affect the value of stringName itself.

例子

The following 例子 both yield "alphabet".

var upperText="ALPHABET"
document.write(upperText.toLowerCase())

"ALPHABET".toLowerCase()

相关

The top property is a synonym for the top-most Navigator window, which is a "document window" or "Web Browser window."

语法

1. top.propertyName
2. top.methodName
3. top.frameName
4. top.frames[index]

propertyName is defaultStatus, status, or length.
methodName is any method associated with the window object.
frameName and frames[index] are ways to refer to frames.

Property of

window

描述

The top property refers to the top-most window that contains frames or nested framesets. Use the top property to refer to this ancestor window.

The top property is read-only. The value of the top property is

     <object objectReference>

例子

The statement top.close() closes the top-most ancestor window.

The statement top.length specifies the number of frames contained within the top-most ancestor window. When the top-most ancestor is defined as follows, top.length returns 3:

<FRAMESET COLS="30%,40%,30%">
<FRAME SRC=child1.htm NAME="childFrame1">
<FRAME SRC=child2.htm NAME="childFrame2">
<FRAME SRC=child3.htm NAME="childFrame3">
</FRAMESET>

The following example sets the background color of a frame called myFrame to red. myFrame is a child of the top-most ancestor window.

top.myFrame.document.bgColor="red"

Returns the calling string value converted to upper case.

语法

stringName.toUpperCase()

stringName is any string or a property of an existing object.

用法

string

描述

The toUpperCase method returns the value of stringName converted to upper case. toUpperCase does not affect the value of stringName itself.

例子

The following 例子 both yield "ALPHABET".

var lowerText="alphabet"
document.write(lowerText.toUpperCase())

"alphabet".toUpperCase()

相关