visual studio 2010 - Calculating Factorials in C# - No Errors, But Doesn't Work? -

i have simple program supposed calculate factorial of entered number. says have no errors, when run program stalls , not work. can please tell me why?

    private void getfactorial_click(object sender, eventargs e)     {         int usernumber, numberfactorial = 1;          usernumber = int.parse(numberinput.text);         if (usernumber <= 0)         {             numberoutput.text = numberfactorial.tostring();         }         else         {             (int = 1; 1 <= usernumber; i++)             {                 numberfactorial = numberfactorial * i;                 numberoutput.text = numberfactorial.tostring();             }         }     } } 

}

it's simple things us.

in loop have this:

for (int = 1; 1 <= usernumber; i++) 

i believe mean this:

for (int = 1; <= usernumber; i++) 

in conditional part of loop used '1' rather 'i'.