//function to change some styles (eg background colour) of an element when it loses focus in IE
function setBlurStyle(element_id)
{
//no action needed for Opera and Firefox, these browsers handle the style changes
//associated with changes of focus but 
//the CSS pseudo class input:focus is not supported by IE7 and below
//so when the element was given focus, its class was changed to focus_style
//if it was changed, now the element is losing focus, restore its class to input
	if(document.getElementById(element_id).className === "focus_style")
	{
		document.getElementById(element_id).className = "input";
	}
}