You seem confused as to what RAISERROR does: it causes an exception in your C# code,it doesn't return any data to your reader.
And the exception you catch and immediately rethrow means that the exception is passed on up immediately, no dtaa is put into your label because the code to do that is never executed.
Worse, in one case, the code that generates the exception is outside the
try...catch
block, so even if you actually did anything with the exception (which you don't in any case, just re-throw it) it wouldn't be caught in the method anyway!
List<globalVariables> result = imageBL.getEmployeerecord(name);
try
{
...
A non-existent user isn't an error: it's normal processing. It's a spelling mistake by the user maybe - handling it via exceptions is not good practice. And "handling it" by immediately just throwing it again doesn't do anything useful anyway.
Stop and think what you are trying to achieve here: this is very much the wrong approach!