function checkForm(form)
{
    var error = "";
    error += checkEmail(form.emailinput.value);
    error += checkName(form.nameinput.value);
    error += checkArea(form.textareainput.value);

    if (error != "") {
       alert(error);
       return false;
    }
    return true;
}


// email
function checkEmail (strng)
{
    var error="";
    if (strng == "")
	{
        error = "You didn't enter an email address.\n";
    }
    var emailFilter=/^.+@.+\..{2,3}$/;
    if (!(emailFilter.test(strng)))
	{
       error = "Please enter a valid email address.\n";
    }
    else
	{
       //test email for illegal characters
       var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/
       if (strng.match(illegalChars))
	   {
          error = "The email address contains illegal characters.\n";
       }
    }
    return error;
}

// name
function checkName(strng)
{
    var error = "";
    if (strng.length == 0)
	{
        error = "The name field has not been filled in.\n"
    }
    return error;
}

// text area
function checkArea(strng)
{
    var error = "";
    if (strng.length == 0)
	{
        error = "The text area has not been filled in.\n"
    }
    return error;
}