function setHeight() {

    var minheight = 250;
    var colAheight = document.getElementById('cola').offsetHeight;
    var colBheight = document.getElementById('colb').offsetHeight;

    if ((colAheight < minheight) && (colBheight < minheight)) {
        document.getElementById('cola').style.height = minheight
        document.getElementById('colb').style.height = minheight 
    }
    if (colAheight >= colBheight) {
        document.getElementById('colb').style.height = colAheight + 100 + 'px';
    }
    
    
    
}