function isEmpty(elem)
{
	if(elem.value.length == 0)
		return true;
	else
		return false;
}


function isEmail(elem)
{

	var emailExp = /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/;
	if(elem.value.match(emailExp))
		return true;
	else
	{
		elem.focus();
		return false;
	}
}

function isNumeric(elem)
{
	var numericExpression = /^[0-9]+$/;
	if(elem.value.match(numericExpression))
		return true;
	else
		return false;
}

function isZip(elem)
{

	var zipExp = /(^\d{5}$)|(^\d{5}-\d{4}$)/;
	if(elem.value.match(zipExp))
		return true;
	else
	{
		elem.focus();
		return false;
	}
}

function isPhone(elem)
{

	var phoneExp = /[1-9]\d{2}\-\s?\d{3}\-\d{4}$/;
	if(elem.value.match(phoneExp))
		return true;
	else
	{
		elem.focus();
		return false;
	}
}