function chkForm(form, num)
{
	var anum = /(^\d+$)|(^\d+\.\d+$)/;
	var filter = /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i;
	if (num=='contact')
	{
		if (form.name.value=="")
		{
			alert ("Please enter contact name!");
			form.name.focus();
			return false;
		}
		if (form.email.value=="")
		{
			alert ("Please enter email address!");
			form.email.focus();
			return false;
		}
		if (!filter.test(form.email.value))
		{
			alert ("Please enter a valid email address!");
			form.email.select();
			return false;
		}
		if (form.comment.value=="")
		{
			alert ("Please enter your comment!");
			form.comment.focus();
			return false;		
		}
	}
	if (num=='inquiry')
	{
		if (form.qty.value!="" && !anum.test(form.qty.value))
		{
			alert ("Please enter a valid integer!");
			form.qty.select();
			return false;
		}
		if (form.co.value=="")
		{
			alert ("Please enter company name!");
			form.co.focus();
			return false;
		}
		if (form.name.value=="")
		{
			alert ("Please enter contact name!");
			form.name.focus();
			return false;
		}
		if (form.phone.value=="")
		{
			alert ("Please enter contact number!");
			form.phone.focus();
			return false;
		}
		if (form.fax.value=="")
		{
			alert ("Please enter fax number!");
			form.fax.focus();
			return false;
		}
		if (form.email.value=="")
		{
			alert ("Please enter email address!");
			form.email.focus();
			return false;
		}
		if (!filter.test(form.email.value))
		{
			alert ("Please enter a valid email address!");
			form.email.focus();
			return false;
		}
	}
	if (num=="registration")
	{
		if (form.name.value=="")
		{
			alert ("Please enter user name!");
			form.name.focus();
			return false;
		}
		if (form.model.value=="select")
		{
			alert ("Please select product!");
			form.model.focus();
			return false;
		}
		if (form.serial.value=="")
		{
			alert ("Please enter serial number!\nIf serial not found, enter '000'");
			form.serial.focus();
			return false;
		}
		if (form.year.value=="year" || form.month.value=="month" ||form.day.value=="day")
		{
			alert ("Please select valid date!");
			form.year.focus();
			return false;
		}
	}
	return true;
}