var c=720;
var l=((window.innerWidth-c)/2)-10;

var r=l;
var table="";
table+="<div style='width:"+l+"px;'>";
table+="</div></td>";

document.write(table);


/*

document.writeln(window.innerWidth+"-"+l+"-"+c+"-"+r);


var colgroup="<colgroup> ";

colgroup+="<col width='"+l+"'>";
colgroup+="<col width='"+c+"'>";
//colgroup+="<col width='"+r+"'>";
colgroup+="<col>";

alert(window.outerWidth+"-"+l+"-"+c+"-"+r);
*/