need help regarding focus() in .htc file

[trip_jitendra]

I am using the following code:

<PUBLIC:ATTACH EVENT=oncontentready ONEVENT="fnOnMouseOver()">
<PUBLIC:ATTACH EVENT=onmouseover HANDLER="onmouseover_handler"/>

function fnOnMouseOver()
{

onmouseover_handler();
}

function onmouseover_handler()
{
var elem = event.srcElement;

if (elem.tagName != undefined && elem.tagName.toUpperCase() == "BUTTON")
{
if (elem._control == undefined || elem._control.IsDisabled())
return;
elem.focus();

}
//fnOnMouseOut();
}

Now the problem is I am unable to remove the focus when mouse is out from the button. I have already tried blur() but it didn't worked. :confused:
CAN ANYBODY HELP ME OUT