var Input = {
initialize: function() {
  if(document.getElementsByTagName("form")) {
      var divs = document.getElementsByTagName("div");
      for(var i = 0; i < divs.length; i++) {
        if(divs[i].className.match("checkbox") || divs[i].className.match("radio")) {
           divs[i].onmousedown = Input.effect;
           divs[i].onmouseup = Input.handle;
           window.onmouseup = Input.clear;
         }
       }
     }
   },

   effect: function() {
     if(this.className == "checkbox" || this.className == "radio") {
       this.style.backgroundPosition = "0 -26px";
     } else {
       this.style.backgroundPosition = "0 -79px";
     }
   },

   handle: function() {
     selector = this.getElementsByTagName("input")[0];
     if(this.className == "checkbox") {
       selector.checked = true;
       this.className = "checkbox selected";
       this.style.backgroundPosition = "0 -52px";
     } else if(this.className == "checkbox selected") {
       selector.checked = false;
       this.className = "checkbox";
       this.style.backgroundPosition = "0 0";
     } else {
       selector.checked = true;
       this.className = "radio selected";
       this.style.backgroundPosition = "0 -52px";
       inputs = document.getElementsByTagName("input");
       for(i = 0; i < inputs.length; i++) {
         if(inputs[i].getAttribute("name") == selector.getAttribute("name")) {
           if(inputs[i] != selector) {
             inputs[i].parentNode.className = "radio";
             inputs[i].parentNode.style.backgroundPosition = "0 0";
           }
         }
       }
     }
   },

   clear: function() {
     divs = document.getElementsByTagName("div");
     for(var i = 0; i < divs.length; i++) {
       if(divs[i].className == "checkbox" || divs[i].className == "radio") {
         divs[i].style.backgroundPosition = "0 0";
       } else if(divs[i].className == "checkbox selected" || divs[i].className == "radio selected") {
         divs[i].style.backgroundPosition = "0 -52px";
       }
     }
   }
 }
 window.onload = Input.initialize;