function validEmpty(formField)
{
	var result = false;
	
	if (formField.value == "")
	{
		result = true;
	}
	
	return result;
}

function validRequired(formField,fieldLabel)
{
	var result = true;
	
	if (formField.value == "")
	{
		alert('Please enter a value for the "' + fieldLabel +'" field.');
		formField.focus();
		result = false;
	}
	
	return result;
}

function allDecimalDigits(str)
{
	return inValidCharSet(str,"0123456789.");
}

function allDigits(str)
{
	return inValidCharSet(str,"0123456789");
}

function allDigitsNSpaces(str)
{
	return inValidCharSet(str,"0123456789 ");
}

function inValidCharSet(str,charset)
{
	var result = true;

	// Note: doesn't use regular expressions to avoid early Mac browser bugs	
	for (var i=0;i<str.length;i++)
		if (charset.indexOf(str.substr(i,1))<0)
		{
			result = false;
			break;
		}
	
	return result;
}


function validNum(formField,fieldLabel,required)
{
	var result = true;

	if (required && !validRequired(formField,fieldLabel))
		result = false;
  
 	if (result)
 	{
 		if (!allDecimalDigits(formField.value))
 		{
 			alert('Please enter a number for the "' + fieldLabel +'" field.');
			formField.focus();		
			result = false;
		}
	} 
	
	return result;
}


function validInt(formField,fieldLabel,required)
{
	var result = true;

	if (required && !validRequired(formField,fieldLabel))
		result = false;
  
 	if (result)
 	{
 		var num = parseInt(formField.value, 10);
 		if (isNaN(num))
 		{
 			alert('Please enter a number for the "' + fieldLabel +'" field.');
			formField.focus();		
			result = false;
		} else {
		
 			if (!allDigits(formField.value))
 			{
 				alert('Please enter a number for the "' + fieldLabel +'" field.');
				formField.focus();		
				result = false;
			}		
		
		}
	} 
	
	return result;
}

function validPhoneNumber(formField,fieldLabel,required)
{
	var result = true;

	if (required && !validRequired(formField,fieldLabel))
		result = false;
  
 	if (result)
 	{
 		var num = parseInt(formField.value, 10);
 		if (isNaN(num))
 		{
 			alert('Please enter a number for the "' + fieldLabel +'" field.');
			formField.focus();		
			result = false;
		} else {
		
 			if (!allDigitsNSpaces(formField.value))
 			{
 				alert('Please enter a number for the "' + fieldLabel +'" field.');
				formField.focus();		
				result = false;
			}		
		
		}
	} 
	
	return result;
}