function checkYear(year) {
  year = parseInt(year, 10);
  if (year < 20)
     year = year + 2000;

  if (year < 100)
     year = year + 1900;

  return year;
}

function notEmpty(name, value) {
  if ((value != null) && (value != ""))
     return true;
  else {
     alert('The ' + name + ' field has been left empty\nPlease fill it in before submitting');
     return false;
  }
}

function notEmptyNA(name, value) {
 if ((value != null) && (value != ""))
    return true;
 else {
    return false;
 }
}

function radioNotEmpty(name, value1, value2) {
  if ((value1) || (value2))
     return true;
  else {
     alert('The ' + name + ' field has been left empty\nPlease fill it in before submitting');
     return false;
  }
}

function notEqual(name1, value1, name2, value2) {
  if (value1 != value2)
     return true;
  else {
     alert('The ' + name1 + ' field is the same as the ' + name2 + ' field.\nPlease make them unique');
     return false;
  }
}

function checkDemo() {
  with (document.gbform) {
		 	if (DemoRequest.checked == true) {
				  if (RequestInfoOn.checked == true)
		       return true;
		    else {
		       alert('Product Demo requires selection of product information.\nPlease select one or more products from the list.');
		       return false;
		    }
		  }
		  else {
		    return true;
		  }
		}
}

function AddressNeeded() {
  with (document.gbform) {
		 	if ((notEmptyNA("RequestInfoOn", RequestInfoOn.value)) || 
				    (Requested.checked == true)) 
		       return true;
		  else
		    return false;
		}
}


function validate() {
  with (document.gbform) {
    if ((notEmpty("First Name", FirstName.value)) &&
        (notEmpty("Last Name", LastName.value)) &&
        (notEqual("First Name", FirstName.value, "Last Name", LastName.value)) &&
        (notEmpty("Customer Type", CustomerType.options[CustomerType.selectedIndex].value))) 
		{
					    	if (AddressNeeded()) {
									    if ((notEmptyNA("Address", Address.value)) && 
													    (notEmptyNA("City", City.value)) &&
									        (notEmptyNA("State", State.options[State.selectedIndex].value)) &&
								 	       (notEmptyNA("Zip", Zip.value)))										  
						      	  		submit();
											  else {
												     alert('Product Literature is mailed. Address, City, State and Zip must be filled in.');
													    return;
			          }
			       }
								  else 
							      submit();
   	}
	   else
				  return;
		}
}

function validate_con() {
  with (document.gbform) {
    if ((notEmpty("First Name", FirstName.value)) &&
        (notEmpty("Last Name", LastName.value)) &&
        (notEqual("First Name", FirstName.value, "Last Name", LastName.value)) &&
        (checkDemo())) {
					    	if (AddressNeeded()) {
									    if ((notEmptyNA("Address", Address.value)) && 
													    (notEmptyNA("City", City.value)) &&
									        (notEmptyNA("State", State.options[State.selectedIndex].value)) &&
								 	       (notEmptyNA("Zip", Zip.value)))										  
						      	  		submit();
											  else {
												     alert('Product Literature is mailed. Address, City, State and Zip must be filled in.');
													    return;
			          }
			       }
								  else 
							      submit();
   	}
	   else
				  return;
		}
}