// JScript File

function checkEmail()
{
    if (isEmpty(document.getElementById('txtfirst'),"First name") &&
        isEmpty(document.getElementById('txtlast'),"Last name") && 
        isNumOpt(document.getElementById('txtphone'),"Phone number") &&
            isPhoneLength(document.getElementById('txtphone'),"Phone number",10) &&
            isEmpty(document.getElementById('txtemail'),"Email") && isValidEmail(document.getElementById('txtemail'))
            )
    {
        return true;
    }
    else
    {
        return false;
    }
}

function isEmpty(field,msg)
{
    if (field)
    {
        if(field.disabled == false)
        {
            if (field.value.length!=0 && field.value!=null)
            {
                return true;
            }
            else
            {
                alert(msg + " is required");
                field.focus = true;
                return false;         
            }
        }
        else
        {
            return true;
        }
    }
    else
    {
        return true;
    }
}

function isPhoneLength(field,msg,num)
{
    if (field.value.length !=0 && field.value != null)
    {
        if(field.value.length == 10)
        {
            return true;
        }
        else
        {
            alert(msg + " must be " + num + " digits long");
            return false; 
        }
    }
    else
    {
        return true;
    }
}

function isValidEmail(field) {
	if (field.value.length!=0 && field.value!=null)
		{
		var emailFilter=/^.+@.+\..{2,4}$/;
		if (!(emailFilter.test(field.value))) { 
			field.focus();
	      	alert("Please enter a valid email address.");
			return false;
		}
		var illegalChars= /[\(\)\<\>\,\;\:\\\/\"\[\]]/
		if (field.value.match(illegalChars)) {
			field.focus();
	   		alert("The email address contains illegal characters.");
			return false;
		}
	}
	return true;
}

function isNumOpt(field,msg) {
// if it's not blank then check if it's numeric
	if (field.value.length!=0 && field.value!=null)
	{
		var strValidChars = "0123456789";
		var strChar;
		var len = field.value.length;
		//  test field consists of valid characters listed above
		for (i = 0; i < len; i++)
		{
		strChar = field.value.charAt(i);
		if (strValidChars.indexOf(strChar) == -1)
			{
			alert(msg + " must be numeric");
			field.focus();
			return false;
			}
		}
		return true;
	}
	else
	{
		return true;
	}
}