The program is probably doing what you want it to, but it's just doing it too fast. If you have no wait time between the if statement, then as soon as you press the button, the processor is so fast that the servo value goes to max before you can blink. I seem to recall that ROBOTC has a servo change rate variable in the servo debugger, but I could be wrong. If not, you can use a simple bit of code to slow down the servo. Here's an example:
This will only check and update the servo every 50ms without interrupting your other functions with lag. You can change the 50 to make the servo move faster or slower. Hope that helps.