function validate_required(field,alerttxt)
{
    with (field)
    {
        if (value==null||value=="")
        {
            alert(alerttxt);return false;
        }
        else
        {
            return true;
        }
    }
}

function validate_form(thisform)
{
    with (thisform)
    {
        if (validate_required(store_location,"Store location must be filled out")==false)
        {
            store_location.focus();return false;
        }
        else if (validate_required(visit_date,"Date and time of visit must be filled out")==false)
        {
            visit_date.focus();return false;
        }
        else if (validate_required(name,"Name must be filled out")==false)
        {
            name.focus();return false;
        }
        else if (validate_required(email,"Email must be filled out")==false)
        {
            email.focus();return false;
        }
    }
}