var now_w = document.body.clientWidth;
var min_w = 1000;
var pre_time = 0;
if(now_w>min_w) document.write("<style>#main{width:100%;}</style>");	
window.onresize = function (){	
	if ( new Date().getTime() - pre_time >300){	
		now_w = document.body.clientWidth;				
		$("main").style.width = (now_w>min_w) ? "100%" : min_w+"px";		
	}	
	pre_time = new Date().getTime();
}