function Start()
{
	var w = document.getElementById("tbl_main").offsetWidth;
	var h = document.getElementById("tbl_main").offsetHeight;
	var relW = (w - 830)/2;
	
	document.getElementById("td_center_main").width = 830;
	document.getElementById("td_left_main").width = relW;
	document.getElementById("td_right_main").width = relW;
}