Find js function with firebug

Question

I have the following button:

<input type="submit" id="btnLogin" onclick="return ValidateLogin();" value="Enter"> 

How can i find the definition of the ValidateLogin() function with firebug?

Answer 1

Type the following into the Firebug Console, then click the function() in the output window

var s = ValidateLogin.prototype.constructor; console.log(s); // will output the actual function definition  

I have included some screenshots to help.