hi? how do i repeatedly run an external file with arguments in a java program?

example, i have to run an exe file named visual which takes in 3 arguments: label, ski, labeloutput:

visual -din label -cout skin -dout labeloutput

i have to put this in a loop and change label and labeloutput for every loop. when i make it dis way:

Runtime rt = Runtime.getRuntime ();
Process proc = rt.exec ("visual -din" + label + ".dat -cout skin.cod -dout" + labeloutput);

it does not work anymore and the process ends even before it's finished.how do i solve this? thank you.