function IsNumeric(sText)
{
   var ValidChars = "0123456789.";
   var IsNumber=true;
   var Char;

 
   for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsNumber = false;
         }
      }
   return IsNumber;
   
}


function IsEmpty(aTextField) {
   if ((aTextField.value.length==0) ||
   (aTextField.value==null)) {
      return true;
   }
   else { return false; }
}

function isValidEmail(str) {
   //return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
	 return (str.indexOf(" ")==-1 && ( str.indexOf(".") > 0 && str.indexOf("@") > 0 ) );
}

function isValidUniqueEmail(str) {
	 return ( (str.indexOf(" ")==-1 && (str.indexOf(",")==-1 && str.indexOf(";")==-1) ) && ( str.indexOf(".") > 0 && str.indexOf("@") > 0 ) );
}

function ValidateContactForm(form){
	if(IsEmpty(form.nombre)) 
	{ 
		alert('Please enter your name.') 
		form.nombre.focus(); 
		return false; 
	}
	if(IsEmpty(form.email)) 
	{ 
		alert('Please enter your email address.') 
		form.email.focus(); 
		return false; 
	} 
	
	
	if (!isValidUniqueEmail(form.email.value)) 
	{ 
		alert('Please enter a valid email address.') 
		form.email.focus(); 
		return false; 
	} 
	
	form.enviar.value="Please wait...";
	form.enviar.disabled=true;
	return true;
 
} 

function ValidateNewsletterForm(form){
	if(IsEmpty(form.nombre)) 
	{ 
		alert('Please enter your name.') 
		form.nombre.focus(); 
		return false; 
	}
	if(IsEmpty(form.email)) 
	{ 
		alert('Please enter your e-mail.') 
		form.email.focus(); 
		return false; 
	} 
	if (!isValidUniqueEmail(form.email.value)) 
	{ 
		alert('Please enter a valid email address.') 
		form.email.focus(); 
		return false; 
	} 
	if(form.email.value!=form.email2.value){
		alert('Your email address does not coincide.') 
		form.email.focus(); 
		return false; 
	}
	
	form.enviar.value="Please wait...";
	form.enviar.disabled=true;
	return true;
 
}