use of javascript in .net

Example of The CustomValidator Control in .net

The CustomValidator control performs its validation based on custom validation code
that you provide.You can write the client-side validation code using JavaScript or
server-side validation code using your preferred .NET language.

In the following code example, a Web page contains a TextBox called txtPassword,
an associated CustomValidator called cusCheckPassword, and a RequiredFieldValidator
called reqPassword because the custom script will not execute if a password is not entered.
A valid password must be between 6 and 14 characters and must contain at least one
uppercase letter, one lowercase letter, and one numeric character. A ValidationSummary
has also been added to the bottom of the Web page to show the validation error.

JavaScript Client-Side Validation

<script language="javascript" type="text/javascript">
function ValidatePassword(source, arguements)
{
var data = arguements.Value.split('');
//start by setting false
arguements.IsValid=false;
//check length
if(data.length < 6 || data.length > 14) return;
//check for uppercase
var uc = false;
for(var c in data)
{
if(data[c] >= 'A' && data[c] <= 'Z')
{
uc=true; break;
}
}
if(!uc) return;
//check for lowercase
var lc = false;
for(var c in data)
{
if(data[c] >= 'a' && data[c] <= 'z')
{
lc=true; break;
}
}
if(!lc) return;
//check for numeric
var num = false;
for(var c in data)
{
if(data[c] >= '0' && data[c] <= '9')
{
num=true; break;
}
}
if(!num) return;
//must be valid
arguements.IsValid=true;
}
</script>


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