addEvent(window, 'load', centerWelcome);

function centerWelcome()
{
	if(typeof(window.innerHeight) == 'number')
	{
    	//Non-IE
    	windowHeight = window.innerHeight;
  	}
	else if(document.documentElement && (document.documentElement.clientWidth || document.documentElement.clientHeight))
	{
		//IE 6+ in 'standards compliant mode'
		windowHeight = document.documentElement.clientHeight;
  	}
	else if(document.body && (document.body.clientWidth || document.body.clientHeight))
	{
		//IE 4 compatible
    	windowHeight = document.body.clientHeight;
  	}
	
	objWelcomeTable = document.getElementById("welcome_table");
	objWelcomeTable.style.top = (windowHeight - objWelcomeTable.clientHeight)/2 + "px";
}

function addEvent(obj, evType, fn)
{ 
	if(obj.addEventListener)
	{ 
		obj.addEventListener(evType, fn, false); 
   		return true; 
 	}
	else if(obj.attachEvent)
	{ 
   		var r = obj.attachEvent("on"+evType, fn); 
   		return r; 
 	}
	else
	{ 
   		return false; 
	} 
}