function doBlink() {
var blink = document.all.tags("BLINK")
for (var i=0; i < blink.length; i++)
    blink[i].style.visibility = blink[i].style.visibility == "" ? "hidden" : "" 
}

function startBlink() {
  // Make sure it is IE4
  if (document.all)
    setInterval("doBlink()",700)
}
window.onload = startBlink;
	function validatePrompt (Ctrl, PromptStr) {	
	alert (PromptStr)	
	Ctrl.focus();	
	return;
}
function checkEmail(field) {
  if (field.value.indexOf("@") == -1) {
    alert("Por favor escriba un E_Mail valido");
	field.focus();
	field.blur();
	field.select();
  }}