Sally, i2dx's suggestion is right. In the Front Panel, you can place the 4 buttons in a cluster and you will control them by the cluster. Let's look at my VI. I have 4 buttons: Configure, Read, Write, Stop(to stop the VI).
4 buttons' Front panel
In the Block Diagram, you place the cluster into the Case Loop. Besides, you should place the Case loop inside a While loop with Shift Register in order to run the VI continuously back and forth. You make the case including cluster the Default Case so that the VI will hold on until you press any button. You can add 4 next cases 1,2,3,4 to make function of 4 buttons. The Cluster in the block diagram is wired to the function"Cluster to Array" and continued wiring to function "Search 1D Array" and in the end to the Shift Register of While loop like this:
4 buttons' Block Diagram- Case Default
The next cases could be like this:
4 buttons' Block Diagram - normal case
You should check the SubVI- here is "configure.vi"- 's property "Windows Appearance" to "Open when called" and check also the Originally check... so as to open the VI automatically. Your purpose is to return from SubVI(another VI) to the main VI. This is simple because you have to do only one thing: adding the stop or cancel button to the SubVI. Once you press that button, the SubVI automatically stop and return to the main VI.
The last VI should be the empty VI. That is the affection of Stop button in the main VI. It helps the main VI stop the while loop and end up the VI. Like this:
button Stop
It is easy. Plz do as I deal with this problem before.
Good luck!
PS: I uploaded this file by YOUSENDIT 'coz I dont know how to insert image. This uploading site will expire in 14 days. Sorry for the inconvenience.