var linkWindows;

function send_mes(id, table)
{
    var w_width  = 500;
    var w_height = 400;
    if (screen) {
    	x = (screen.availWidth - w_width) / 2;
    	y = (screen.availHeight - w_height) / 2;
    }

    if (typeof(linkWindows) == 'undefined' || linkWindows.closed) {
        linkWindows = window.open('send_mes.php?id='+id+'&table='+table, "Link", "toolbar=0, location=0, directories=0, status=0, menubar=0, scrollbars=0, resizable=0, width="+w_width+", height="+w_height+", left="+x+", top="+y+"");
    } else {
        linkWindows.focus();
    }
}