Validering
Jeg er ved at prøve at validere nogle bruger input, men jeg har det problem at strengen:document.PurchaseForm.CCNumber.length returnerer 'Undefined' selvom jeg har indtastet cifre i input boxen. Her er min kode:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>Purchase ucsign</title>
<SCRIPT LANGUAGE="JavaScript">
<!--
function but_OnClick()
{
if (document.PurchaseForm.Firstname.length == 0)
{
alert("You must enter a firstname");
return false
}
if (document.PurchaseForm.Lastname.length == 0)
{
alert("You must enter a lastname");
return false
}
if (document.PurchaseForm.EmailAddress.length == 0)
{
alert("You must enter an e-mail address");
return false
}
if (document.PurchaseForm.CCNumber.length != 16)
{
alert("Invalid Credit Card Number. You entered " + document.PurchaseForm.CCNumber.Length + " digits.");
return false
}
}
//-->
</SCRIPT>
</head>
<body>
<!--Screen Table-->
<TABLE CELLPADDING="0" CELLSPACING="0" BORDER="0">
<TR>
<TD BGCOLOR="#000000" WIDTH="50%"></TD>
<TD BGCOLOR="#000000">
<img src="i/enterdetails.gif" width="520" height="460" border="0">
</TD>
<TD BGCOLOR="#000000" WIDTH="50%"></TD>
</TR>
<TR>
<TD BGCOLOR="#000000"></TD>
<TD BGCOLOR="#000000">
<!--Form Table-->
<TABLE CELLPADDING="0" CELLSPACING="0" BORDER="0">
<TR><TD BGCOLOR="#000000"><img src="i/Spacer.gif" width="125" height="1" border="0">
</TD><TD>
<FORM NAME="PurchaseForm" ACTION="thankyou.asp" METHOD="POST">
<FONT COLOR="#FFFF00">
Firstname:<img src="i/Spacer.gif" width="60" height="1" border="0">
<INPUT TYPE="TEXT" NAME="Firstname" MAXLENGTH="30"><BR><BR>
Lastname:<img src="i/Spacer.gif" width="61" height="1" border="0">
<INPUT TYPE="TEXT" NAME="Lastname" MAXLENGTH="30"><BR><BR>
E-mail Address:<img src="i/Spacer.gif" width="25" height="1" border="0">
<INPUT TYPE="TEXT" NAME="EmailAddress" MAXLENGTH="50"><BR><BR>
Creditcard Number: <INPUT TYPE="TEXT" NAME="CCNumber" MAXLENGTH="30"><BR><BR>
Expires Month:<img src="i/Spacer.gif" width="30" height="1" border="0">
<SELECT NAME="ExpMonth"><OPTION VALUE="01">01</OPTION>
<OPTION VALUE="02">02</OPTION>
<OPTION VALUE="03">03</OPTION><OPTION VALUE="04">04</OPTION>
<OPTION VALUE="05">05</OPTION><OPTION VALUE="06">06</OPTION>
<OPTION VALUE="07">07</OPTION><OPTION VALUE="08">08</OPTION>
<OPTION VALUE="09">09</OPTION><OPTION VALUE="10">10</OPTION>
<OPTION VALUE="11">11</OPTION><OPTION VALUE="12">12</OPTION></SELECT>
<img src="i/Spacer.gif" width="10" height="1" border="0">Year:
<img src="i/Spacer.gif" width="8" height="1" border="0">
<SELECT NAME="ExpYear"><OPTION VALUE="02">02</OPTION>
<OPTION VALUE="03">03</OPTION><OPTION VALUE="04">04</OPTION>
<OPTION VALUE="05">05</OPTION><OPTION VALUE="06">06</OPTION>
<OPTION VALUE="07">07</OPTION><OPTION VALUE="08">08</OPTION>
<OPTION VALUE="09">09</OPTION><OPTION VALUE="10">10</OPTION></SELECT>
<BR><BR>
<img src="i/Spacer.gif" width="60" height="1" border="0">
<input border="0" src="i/b-Purchase.gif" name="I1" type="image"
onclick="return but_OnClick()"><BR><BR>
</FONT>
</FORM></TD></TR>
<!--Form Table-->
</TABLE>
</TD>
<TD BGCOLOR="#000000"></TD>
</TR>
<!--Screen Table-->
</TABLE>
</body>
</html>
