Opening external application from user input

Question

I want to be able to open an application like internet, notepad, iTunes, and any other .exe file from use input.

Right now I got this; (ext is the user input)

try
{
    Process p = Runtime.getRuntime().exec(ext + ".exe");
}
catch(Exception e1){   }

This, however, only seems to be able to open notepad, is there any way I can make it so it can open any installed .exe file?

[NOTE]

I'm trying to do this from a java-window I created

Answer 1

For example this line runs Skype

Process p = Runtime.getRuntime().exec("C:/Program Files (x86)/Skype/Phone/skype.exe");