My answer is not directly to your question. It is advice.
You should not use try catch for logic realization. Program languages (Java, c#, python etc) have if ... else statements. And you can use them for your problem.

not debugged code, simply for example 

    if(slogin.passwordField1.Existed)
    { 
    return slogin.passwordField1;
    } else 
    {
    return slogin.passwordField2;
    }

You can find how realize existed property in Internet (it is easy) and you will levelup you developer skills