margin-top Attribute | marginTop参数属性

Sets or retrieves the height of the top margin of the object.

dhtml语法

HTML { margin-top : sHeight }
Scripting object.style.marginTop [ = sHeight ]

DHTML可能的值

sHeight Variant that specifies or receives one of the following values.
auto Default. Top margin is set equal to the bottom margin.
height Floating-point number, followed by an absolute units designator (cm, mm, in, pt, pc, or px) or a relative units designator (em or ex). For more information about the supported length units, see css length units reference.
percentage Integer, followed by a percent sign (%). The value is a percentage of the height of the parent object.
The property is read/write for all objects except the following, for which it is read-only: currentStyle. The property has a default value of auto. The Cascading Style Sheets (CSS) attribute is not inherited.
Expressions can be used in place of the preceding value(s), as of Microsoft® Internet Explorer 5. For more information, see about dynamic properties.

remarks

as of microsoft® internet explorer 4.0 or later, you can specify possible length values relative to the height of the element's font (em) or the height of the letter "x" (ex).
in internet explorer 3.0, the specified margin value is added to the default value of the object. in internet explorer 4.0 or later, the margin value is absolute. the margin properties do not work with the td and tr objects in internet explorer 4.0, but they do work in internet explorer 3.0. to set margins in the cell for internet explorer 4.0 or later, apply the margin to an object, such as div or p, within the td.
as of internet explorer 5.5, this property applies to inline elements. with earlier versions of internet explorer, inline elements must have an absolute?a href="../properties/position.html">position or layout to use this property. element layout is set by providing a value for the height property or the width property.
for inline elements, the value of this property is used to compute the border area of a surrounding inline element, if present. this value does not contribute to the height of a line.
negative margins are supported, except for top and bottom margins on inline objects.

Examples

The following examples use the margin-top attribute and the marginTop property to change the margin of the object.
This example uses hr as a selector and margin1 as a class in an embedded style sheet to set the top margin of the horizontal rule.
<STYLE>
HR { margin-top:2cm }
.margin1 { margin-top:4cm }
</STYLE>
</HEAD>
<BODY>
<HR onclick="this.className='margin1'" ondblclick="this.className=''">
</STYLE>
This feature requires Microsoft® Internet Explorer 4.0 or later. Click the following icon to install the latest version. Then reload this page to view the sample.
This example uses inline scripting to set and reset the margin when the onclick and ondblclick events occur, respectively.
<hr onclick="this.style.margintop='2cm'"
ondblclick="this.style.marginTop=''">
This feature requires Microsoft® Internet Explorer 4.0 or later. Click the following icon to install the latest version. Then reload this page to view the sample.

是否符合公共标准

This property is defined in Cascading Style Sheets (CSS), Level 1 (CSS1) .

Applies To

A, ACRONYM, B, BDO, BIG, BLOCKQUOTE, BODY, BUTTON, CAPTION, CENTER, CITE, CODE, currentStyle, CUSTOM, DD, defaults, DEL, DFN, DIR, DIV, DL, DT, EM, EMBED, FIELDSET, FONT, FORM, hn, HR, I, IFRAME, IMG, INPUT type=button, INPUT type=checkbox, INPUT type=file, INPUT type=image, INPUT type=password, INPUT type=radio, INPUT type=reset, INPUT type=submit, INPUT type=text, INS, ISINDEX, KBD, LABEL, LI, LISTING, MARQUEE, MENU, NOBR, OBJECT, OL, P, PLAINTEXT, PRE, Q, runtimeStyle, S, SAMP, SMALL, SPAN, STRIKE, STRONG, style, SUB, SUP, TABLE, TD, TEXTAREA, TH, TT, U, UL, VAR, XMP

更多语法参考

css length units reference, CSS Enhancements in Internet Explorer 6