function randomHeader(){
	if(!document.styleSheets) return;
	var bg;
	if(document.styleSheets[0].cssRules){ //Firefox
	//alert(document.styleSheets[0].cssRules[12].cssText);
		bg = document.styleSheets[0].cssRules[13];
	}else if (document.styleSheets[0].rules){ //ie
		bg = document.styleSheets[0].rules[14];
	}else{
		return;
	}
	do{
		var num = Math.round(Math.random()*10);
	}while(num >= 10);
//	alert(bg.style.backgroundImage.length);
	if(bg.style.backgroundImage.length > 0){
		bg.style.backgroundImage = "url(../images/header"+num+".jpg)";
	}
	
} 
randomHeader();