<div1>
<div11/>
<div12/>
<div13/>
</div1>
--------
<div2>
<div21/>
<div22/>
<div23/>
</div2>
----------
<div3>
<div31/>
<div32/>
<div33/>
</div3>
function setEqualHeight(columns){
var tallestcolumn = 0;
columns.each(function(){
currentHeight = $(this).height();
if(currentHeight > tallestcolumn){
tallestcolumn = currentHeight;
}
});
columns.height(tallestcolumn);
}
$(document).ready(function(){
setEqualHeight($(".div1, .div3"));
setEqualHeight($(".div2, .div4"));
})