C Sharp :: Sum Of 2 Textboxes And Then Getting Total In Last Textbox

I am trying to get 2 numbers from 2 textboxs and get a return sum in the third textbox. the strange thing is that i got it to work with this code that i am going to provide on the last app i worked on, now on the new app i am on it doesnt work at all.. I am not getting any Errors, just shows a zero when i calculate to the sum of the total textbox.

int sum1 = 0;
            int sum2 = 0;
            int result = 0;  
            if (int.TryParse(txtPrice.Text, out sum1) & int.TryParse(txtQuantity.Text, out sum2))
                result = sum1 * sum2;
            txtSubTotal.Text = result.ToString();