var windowheight = jQuery(window).height();
var headerheight = jQuery("#column_1").height();
var footerheight = jQuery("#column_2").height();
var layoutheight = jQuery("#column_1").height();
if ( windowheight > layoutheight ) {
var newmiddleheight = windowheight - headerheight - footerheight - 43;
jQuery("#column_1").css({height: newmiddleheight + "px"});
}