$(function()
	{
		$('#opciones li')
			.css( {backgroundPosition: ""} )
			.mouseover(function(){
				$(this).stop().animate({backgroundPosition:"(0 -250px)"}, {duration:500})
			})
			.mouseout(function(){
				$(this).stop().animate({backgroundPosition:"(0 0)"}, {duration:500})
			})
		});
	

function isEmpty(s)
{
	return ((s == null) || (s.length == 0));
}
function isSpace(c)
{
	return ((c == "\n") || (c == " ") || (c == "\b") || (c == "\t"));
}
function isWhiteSpace(s)
{
	for(i=0; i<s.length; i++)
	{
		if(!isSpace(s.charAt(i)))
		{
			return false;
		}
		return true;
	}
}

function warning(f,s)
{
	f.focus();
	f.select();
	alert(s);
	return false;
}

function isEmail(email)
{
   var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
   if(reg.test(email) == false)
   {
       return false;
   }
}

function validar()
{
	var fm = document.form1;
  var First_name = fm.First_name.value;
  var Last_name = fm.Last_name.value;
  var Email = fm.Email.value;
  var Phone = fm.Phone.value;
  
  if(isEmpty(First_name))
    return (warning(fm.First_name,"Please enter your First Name."));
  if(isEmpty(Last_name))
    return (warning(fm.Last_name,"Please enter your Last Name."));
	if(isEmpty(Phone))
    return (warning(fm.Phone,"Please enter your Phone."));
	 if(isEmail(Email)==false)
    return (warning(fm.Email,"Email address is empty or invalid"));

	return true;
}

function enviar()
{
	if(validar())
	{
       var formulario = document.getElementById("form1");
	   formulario.submit();
	}
}