function isEmpty(s)
{   return ((s == null) || (s.length == 0) || (s == " "))
}

function hasSpaces(s) {
	containsSpaces = false;
	for (i=0; i < s.length; i++){
	      if (s.charAt(i) == " "){
			containsSpaces = true;
			break;
			}
	}
	return (containsSpaces);
}

function get_radio_value(formname, elname) {
for (var i=0; i < document[formname][elname].length; i++)
   {
   if (document[formname][elname][i].checked)
      {
      var rad_val = document[formname][elname][i].value;
      return (rad_val);
	  break;
	  }
   }
}

function gradFormCheck(formName) {
    returntype=false;
    if (isEmpty(document[formName].name.value))
    {
      alert('Please enter your name');
	   document[formName].name.focus();
      return false;
    }

    if (isEmpty(document[formName].email.value))
    {
      alert('Please enter your email address');
	   document[formName].email.focus();
      return false;
    }
	
	
	if (get_radio_value(formName, 'require') =="yes") {
		if (document[formName].tickets.value == 0)
	    {
	      alert('Please select the required number of tickets');
		   document[formName].tickets.focus();
	      return false;
	    }
		if (document[formName].performance.value == 0)
	    {
	      alert('Please select a date and time of the performance you wish to attend');
		   document[formName].performance.focus();
	      return false;
	    }
	}

    return true;
}



function registrationCheck() {
    returntype=false;
    if (isEmpty(document.register.firstname.value))
    {
      alert('Please enter your first name');
	   document.register.firstname.focus();
      return false;
    }
    if (isEmpty(document.register.lastname.value))
    {
      alert('Please enter your last name');
	   document.register.lastname.focus();
      return false;
    }
    if (isEmpty(document.register.email.value))
    {
      alert('Please enter your email address');
	   document.register.email.focus();
      return false;
    }
	if (isEmpty(document.register.telephone.value))
    {
      alert('Please enter a contact telephone number');
	   document.register.telephone.focus();
      return false;
    }
	    if (document.register.paymentmethod.value == 0)
    {
      alert('Please select a payment method');
	   document.register.paymentmethod.focus();
      return false;
    }
	if (document.register.paymentmethod.value == 'C')
    {
		if (isEmpty(document.register.chequenumber.value))
		{
      		alert('Please enter the cheque number');
	  	    document.register.chequenumber.focus();
      		return false;
    	}
		if (isEmpty(document.register.chequeamount.value))
		{
      		alert('Please enter the total amount of the cheque');
	   		document.register.chequeamount.focus();
      		return false;
    	}
	}
	if (document.register.signature.value != document.register.signaturevalidate.value)
    {
      alert('Please check the acceptance code');
	   document.register.signaturevalidate.focus();
      return false;
    }
    return true;
}

function checkPerformance() {
	if ((document.centreform.performance.value == "Thu-14-07@14.30") || (document.centreform.performance.value == "Thu-14-07@19.15")) {
		document.getElementById("showtickets").className = "displayBlock";
	} else {
		document.getElementById("showtickets").className = "displayNone";
	}
}