function getElementsByClassName(className, tag, elm){
	var testClass = new RegExp("(^|\\s)" + className + "(\\s|$)");
	var tag = tag || "*";
	var elm = elm || document;
	var elements = (tag == "*" && elm.all)? elm.all : elm.getElementsByTagName(tag);
	var returnElements = [];
	var current;
	var length = elements.length;
	for(var i=0; i<length; i++){
		current = elements[i];
		if(testClass.test(current.className)){
			returnElements.push(current);
		}
	}
	return returnElements;
}

function addClassName(elm, className){
    var currentClass = elm.className;
    if(!new RegExp(("(^|\\s)" + className + "(\\s|$)"), "i").test(currentClass)){
        elm.className = currentClass + ((currentClass.length > 0)? " " : "") + className;
    }
    return elm.className;
}

function removeClassName(elm, className){
    var classToRemove = new RegExp(("(^|\\s)" + className + "(\\s|$)"), "i");
    elm.className = elm.className.replace(classToRemove, "").replace(/^\s+|\s+$/g, "");
    return elm.className;
}

function hasClass(el, c) {
  if (!el || !el.className.length) return;
  var bits = el.className.split(' '), has = false;
  for (var j = 0; j < bits.length; j++) if (bits[j] === c) has = true;
  return has;
}

function activateThisColumn(column) {
  var table = document.getElementById('pricetable');
  var form = document.getElementById('formcontainer');

  // first, remove the 'on' class from all other th's
  var ths = table.getElementsByTagName('th');
  for (var g=0; g<ths.length; g++) {
    removeClassName(ths[g], 'on');
    if (!hasClass(ths[g],'side')) {
      ths[g].style.display = 'none';
    }
  }
  // then, remove the 'on' class from all other td's
  var tds = table.getElementsByTagName('td');
  for (var m=0; m<tds.length; m++) {
    removeClassName(tds[m], 'on');
    if (!hasClass(tds[m],'side')) {
      tds[m].style.display = 'none';
    }
  }

  // now, add the class 'on' to the selected th
  var newths = getElementsByClassName(column, 'th', table);
  for (var h=0; h<newths.length; h++) {
    addClassName(newths[h], 'on');
    newths[h].style.display = '';
    // not all browsers like display = 'block' for cells
  }
    // and finally, add the class 'on' to the selected td
  var newtds = getElementsByClassName(column, 'td', table);
  for (var i=0; i<newtds.length; i++) {
    addClassName(newtds[i], 'on');
  // populate the product type field
    newtds[i].style.display = '';
    // not all browsers like display = 'block' for cells
  }
  // show the form!
  form.style.display = 'block';
	var choice = document.getElementById('choice');
	choice.value = column;
}

function hideTheForm() {
	// get the form
	var form = document.getElementById('formcontainer');
	// hide the form
	form.style.display = 'none';
	
	// now get the hidden table cells and show them again
	var table = document.getElementById('pricetable');
	var tds = table.getElementsByTagName('td');
	for (var i=0; i<tds.length; i++) {
		tds[i].style.display = '';
	}
	var ths = table.getElementsByTagName('th');
	for (var k=0; k<ths.length; k++) {
		ths[k].style.display = '';
	}
}