Here
are some descriptions of what is done in the above script:
Retrieving
Form Data and Removing Leading and Trailing Whitespaces
The
form data entered by the user is stored in five WML variables:
username, password,
email, name
and birthday. Before validation can be done, we
have to retrieve the value of these WML variables. Any leading and
trailing whitespaces should be removed since we do not want the user
name, the password, etc, to be a few space characters:
var
form_username = String.trim(WMLBrowser.getVar("username")); var
form_password = String.trim(WMLBrowser.getVar("password")); var
form_email = String.trim(WMLBrowser.getVar("email")); var
form_name = String.trim(WMLBrowser.getVar("name")); var
form_birthday = String.trim(WMLBrowser.getVar("birthday"));
Checking Whether
All Required Fields Has been Filled
Then
we use the following WMLScript code to check whether the user has
filled in all the required fields. The WMLScript code is very
straightforward. If any of the variables contains an empty string, we
will assign an error message to the WML variable errorMsg,
refresh the WML browser and quit the validate()
function:
if
(""==form_username){ WMLBrowser.setVar("errorMsg",
"The User Name field must not be
empty."); WMLBrowser.refresh(); return; }
if
(""==form_password){ WMLBrowser.setVar("errorMsg",
"The Password field must not be
empty."); WMLBrowser.refresh(); return; }
if
(""==form_email){ WMLBrowser.setVar("errorMsg",
"The Email field must not be
empty."); WMLBrowser.refresh(); return; }
The
following screenshots show the error message that you will see if you
do not fill in the username field:
 Sony
Ericsson T68i
|
 Nokia
Mobile Browser 4.0
|
Checking the Length
of Password
Next,
the length() function of the
String standard library is used to check the number of characters
contained in the password
variable. If it is fewer than eight, the WML browser will display an
error message to notify the user of the problem:
if
(String.length(form_password) <
8){ WMLBrowser.setVar("errorMsg", "The password
must contain at least 8 characters since a short password is less
secure."); WMLBrowser.refresh(); return; }
The
following screenshots show the error message that you will see if you
enter a password that contains fewer than eight characters:

 Sony
Ericsson T68i
|
 Nokia
Mobile Browser 4.0
|
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