VB.Net - Stop program execution

How can I stop a program from continuing if an error is encountered in my code? I've tried

ActivePartProgram.Quit
ActivePartProgram.Close

but neither have worked... Any ideas?

Seems like there is no need to use the Windows API, apparently the execution dialog objects are exposed through the automation interface:

CancelExecution Presses the Cancel button if enabled  
 Continue Presses the Continue button if enabled  
 EraseHit Presses the Erase Hit button if enabled  
 Jump Presses the Jump button if enabled  
 NewRow Presses the New Row button if enabled  
 ScaleProbe Presses the Scale Probe button if enabled  
 ScanDone Presses the Scan Done button if enabled  
 Skip Presses the Skip button if enabled  
 StepInto Presses the Step Into button if enabled  
 StepNext Presses the Step Next button if enabled  
 stop Presses the Stop button if enabled  
 Watch Presses the Watch button if enabled