//get any existing onload function
var oldonload = window.onload; 
if (typeof window.onload != 'function') { 
	window.onload=function(){
		windowHeight();
	}
} 
else { 
	window.onload = function() { 
		if (oldonload) { 
			oldonload(); 
		} 
		windowHeight(); 
	} 
}		

function windowHeight(){
	/* 	Function to force the outer div to have a minimum height of the screen height, 
		to ensure the fire effect is definitely at the bottom of the screen. */	
	if (document.getElementById('maininner')){
		document.getElementById('maininner').style.minHeight=(screen.height)+'px';
	}	
}