Launching external process

When trying to launch an external processing, I get this error: ""file.java": non-static method exec(java.lang.String) cannot be referenced from a static context at line 317, column 24". Any ideas?

import java.lang.Runtime;

try

{

Runtime.exec("calc");

}catch (IOException ioe)

{

}

[559 byte] By [bronze-starDukes] at [2007-11-26 12:09:58]