matchColumns=function() { 

     var divs, contDivs, maxHeight, divHeight, d;
	 var contDivs2, maxHeight2;
	
     // get all <div> elements in the document
     divs=document.getElementsByTagName('div'); 

     contDivs=[];
	 contDivs2=[];

     // initialize maximum height value 

     maxHeight=0; 
	 maxHeight2=0; 

     // iterate over all <div> elements in the document 

     for(var i=0;i<divs.length;i++) {

          // make collection with <div> elements with class attribute 'container'
          if(/\bcolumn1\b/.test(divs[i].className)) {

                d=divs[i]; 

                contDivs[contDivs.length]=d; 

                // determine height for <div> element
                if(d.offsetHeight) {
                     divHeight=d.offsetHeight;
                } 

                else if(d.style.pixelHeight) {
                     divHeight=d.style.pixelHeight;
                }

                // calculate maximum height 
                maxHeight=Math.max(maxHeight,divHeight); 
          } 
		  
		  // Col 2		  
		  if (/\bcolumn2\b/.test(divs[i].className)) { 

                d=divs[i]; 

                contDivs2[contDivs2.length]=d; 

                // determine height for <div> element
                if(d.offsetHeight) {
                     divHeight=d.offsetHeight;
                } 

                else if(d.style.pixelHeight) {
                     divHeight=d.style.pixelHeight;
                } 

                // calculate maximum height
                maxHeight2=Math.max(maxHeight2,divHeight);
          }
	}
		  
     // assign maximum height value to all of container <div> elements
     for(var i=0;i<contDivs.length;i++) {
          contDivs[i].style.height=maxHeight + "px";
     } 

	// Col 2
     for(var i=0;i<contDivs2.length;i++) {
          contDivs2[i].style.height=maxHeight2 + "px";
     }	 
} 

// Runs the script when page loads 

window.onload = function() {
     if(document.getElementsByTagName) {
          matchColumns();
     }
}