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; 
      } 
    } 
  } 
} 

window.onload = prepareForms;
function prepareForms() { 
  for (var i=0; i<document.forms.length; i++) { 
    var thisform = document.forms[i]; 
    resetFields(thisform); 
  }  
}