function resetFields(whichform) {
  for (var i=0; i<whichform.elements.length; i++) {
    var element = whichform.elements[i];
    if (element.type == "submit") continue;
    if (!element.defaultValue) continue;
    element.onfocus = function() {
    if (this.value == this.defaultValue) {
      this.value = "";
     }
    }
    element.onblur = function() {
      if (this.value == "") {
        this.value = this.defaultValue;
      }
    }
  }
}
function prepareForms() {
  for (var i=0; i<document.forms.length; i++) {
    var thisform = document.forms[i];
    resetFields(thisform);
  }
}

window.onload = function() {
  prepareForms();
  }