I have a call like this:

$("#ContextMenuModal").height($("body").height());

However $("body").height() returns undefined when I view it in Firebug.

What would cause jQuery to return undefined for the body height?

I am using jQuery 1.4.1.

Edit:

This is inside an iFrame

I have a call like this:

$("#ContextMenuModal").height($("body").height());

However $("body").height() returns undefined when I view it in Firebug.

What would cause jQuery to return undefined for the body height?

I am using jQuery 1.4.1.

Edit:

This is inside an iFrame

• javascript
• jquery

• Without seeing a test case, we can only have wild assumptions about what can cause this. Please create a demo or show the page. Here is a demo that shows it working. Your turn. – kapa Commented Jun 13, 2012 at 21:04
• @bažmegakapa It is a large application I am unable to post, I can attempt to create a repro, however, I was wondering if there were cases where jquery cannot determine the height. – dmck Commented Jun 13, 2012 at 21:11
• It's always difficult (mostly impossible?) to find a bug when you cannot see the code and the program running. – kapa Commented Jun 13, 2012 at 21:14
• 2 Are you running this after the page has loaded? – epascarello Commented Jun 13, 2012 at 21:28

2 Answers 2

Simply use

$(document).height() // - $('body').offset().top

and / or

$(window).height()

instead $('body').height()

To expand a bit,

$(window).height();   // returns height of browser viewport
$(document).height(); // returns height of HTML document

As bažmegakapa points out, there is a slight difference, albeit a few pixels. The true height of the body can be calculated by subtracting the body offset from the document height (like I mentioned above):

$(document).height() - $('body').offset().top

Use this-

 $("body").css("height")

well i will say jquery is not needed-

this.style.height;//it will not work if you add it as inline js.