function rollover(imageName,imageSrc)
{
	document[imageName].src=imageSrc;
}

function checkField(requiredField,errorMsg)
{
	with (requiredField)
	{
		if (value==null||value=="")
		{
			alert(errorMsg);return false;
		}
		else
		{
			return true;
		}
	}
}

function checkEmail(emailField,errorMsg)
{
	with (emailField)
	{
		atPosition=value.indexOf("@");
		dotPosition=value.lastIndexOf(".");
		if (atPosition<1||dotPosition-atPosition<2)
		{
			alert(errorMsg);return false;
		}
		else 
		{
			return true;
		}
	}
}

function checkForm(contactform)
{
	with (contactform)
	{
		okToSend.value='yes';
		if (checkField(EnqName,"An name is required")==false)
		{
			EnqName.focus();
			okToSend.value='no';
			return false;
		}
		if (checkEmail(EnqEmail,"An Email address is required")==false)
		{
			EnqEmail.focus();
			okToSend.value='no';
			return false;
		}
		if (checkField(EnqOrg,"An organisation name is required")==false)
		{
			EnqOrg.focus();
			okToSend.value='no';
			return false;
		}
		if (checkField(EnqPhone,"A contact phone number is required")==false)
		{
			EnqPhone.focus();
			okToSend.value='no';
			return false;
		}
		if (checkField(EnqMessage,"Please provide the details of your enquiry")==false)
		{
			EnqMessage.focus();
			okToSend.value='no';
			return false;
		}
	}
}