function removeSpaces(field) {
	while (field.substring(0,1) == ' ') field = field.substring(1);
	while (field.substring(field.length-1,field.length) == ' ') field = field.substring(0,field.length-1);
	return field;
}

function isEmailAddr(email)
{
	var result = false;
	var theStr = new String(email);
	var index = theStr.indexOf("@");
	if (index > 0)
	{
		var pindex = theStr.indexOf(".",index);
		if ((pindex > index+1) && (theStr.length > pindex+1))
		result = true;
	}
	return result;
}

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

function validRequiredImage(formField,fieldLabel)
{
	var result = true;
	if (removeSpaces(formField.value) == "")
	{
		alert('Please select a picture to upload for "' + fieldLabel +'".');
		formField.focus();
		result = false;
	}
	return result;
}

function isValidRequired(formField,fieldLabel)
{
	var result = true;
	if (removeSpaces(formField.value) == "")
	{
		result = false;
	}
	return result;
}

function validDate(formField,fieldLabel,required)
{
	var result = true;
	if (required && !isValidRequired(formField,fieldLabel))
		result = false;
 	if (result && isValidRequired(formField,fieldLabel))
 	{
 		var elems = formField.value.split("/");
 		result = (elems.length == 3); // should be three components
 		if (result)
 		{
 			var day = parseInt(elems[0],10);
  			var month = parseInt(elems[1],10);
 			var year = parseInt(elems[2],10);
			result = allDigits(elems[0]) && (day > 0) && (day < 32) &&
					 allDigits(elems[1]) && (month > 0) && (month < 13) &&
					 allDigits(elems[2]) && ((elems[2].length == 2) || (elems[2].length == 4));
 		}
	}
	if (!result)
	{
 		alert('Please enter a date in the format DD/MM/YYYY for the "' + fieldLabel +'" field.');
		formField.focus();		
	}
	return result;
}

function validTime(formField,fieldLabel,required)
{
	var result = true;
	if (required && !isValidRequired(formField,fieldLabel))
		result = false;
 	if (result && isValidRequired(formField,fieldLabel))
 	{
 		var elems = formField.value.split(":");
 		result = (elems.length == 2); // should be three components
 		if (result)
 		{
 			var hour = parseInt(elems[0],10);
  			var minute = parseInt(elems[1],10);
			result = allDigits(elems[0]) && (hour > -1) && (hour < 25) &&
					 allDigits(elems[1]) && (minute > -1) && (minute < 61);
 		}
	}
	if (!result)
	{
 		alert('Please enter a time in the format HH:MM (24 hour clock) for the "' + fieldLabel +'" field.');
		formField.focus();		
	}
	return result;
}

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

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

function validChecked(formField,fieldLabel)
{
	var result = true;
	if (formField.checked == false)
	{
		alert('Please tick "' + fieldLabel +'" to continue.');
		formField.focus();
		result = false;
	}
	return result;
}

function validRadio(formField,fieldLabel)
{
	var result = true;
	var radioChoice = false;

	for (i=0; i<formField.length; i++)
	{
		if (formField[i].checked)
		{
			radioChoice = true;
		}
	}
	if (!radioChoice)
	{
		alert('Please select "' + fieldLabel +'" to continue.');
		formField[0].focus();
		result = false;
	}
	return result;
}

function validOneToTen(formField)
{
	var result = true;
	var radioChoice = false;

	for (i=0; i<formField.length; i++)
	{
		if (formField[i].checked)
		{
			radioChoice = true;
		}
	}
	if (!radioChoice)
	{
		alert('Please answer all questions to continue.');
		formField[0].focus();
		result = false;
	}
	return result;
}

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

	if (formField.selectedIndex==0)
	{
		alert('Please choose "' + fieldLabel +'" to continue.');
		formField.focus();
		result = false;
	}
	return result;
}
function validEmail(formField,fieldLabel,required)
{
	var result = true;
	if (required && !validRequired(formField,fieldLabel))
		result = false;
	if (result && ((formField.value.length < 3) || !isEmailAddr(formField.value)) )
	{
		alert("Please enter a complete email address in the form: yourname@yourdomain.com");
		formField.focus();
		result = false;
	}
	return result;
}

function validMatch(formField1,fieldLabel1,formField2,fieldLabel2)
{
	var result = true;
	if (removeSpaces(formField1.value) != removeSpaces(formField2.value))
	{
		alert('"' + fieldLabel1 + '" must match "' + fieldLabel2 +'".');
		formField1.focus();
		result = false;
	}
	return result;
}

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

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

function inValidCharSet(str,charset)
{
	var result = true;
	for (var i=0;i<str.length;i++)
		if (charset.indexOf(str.substr(i,1))<0)
		{
			result = false;
			break;
		}
	return result;
}

function submitForm()
{
	if (document.forms[0].onsubmit())
	{
		document.forms[0].submit();
	}
}

function DoPicturePreview()
{
	var filename = document.forms[0].imgPicture.value;
	var Img = new Image();
	Img.src = filename;
	document.images.imgPicturePreview.src = Img.src;
}