This Function is used to Validate the captcha value.
Syntax:
ValidateCaptcha(ControlName,Value)
where
ControlName :Name of the control
(Optional) Value :User input value if user inputs captcha value in another control.
Example:
ValidateCaptcha(Captcha1)
ValidateCaptcha(Captcha1,TxtCaptcha.Value) will return true if both values match.