i have a problem in executing it in another case.. only Case 1 is executing other case is not..

You have to create a switch function with the cases you want and the identifiers (case 1, case 23, case 41...). And then you have to call that cases, if you don't have case 2, you can't execute it. Do you have a correct code inside the case?

robot prog

var 2 =0

switch var 2 = 0

case 1

do something

case 2 do something

end of prog

this is just a simple program created with a switch command.. in this case only case 1 is excuted and case 2 is not.. but I don't know if the program is correct, it is my first tym using switch command..

Unless var2 = 2 then that case will not execute, in your example case 1 would also not execute since var2 == 0. 

If you had a default case in your example when var2 equals anything other than 1 or 2 the default case would execute. 

Hope me this makes sense. Let me know if you need anymore help. 

Try with something like this (pseudocode):

Robot program

option = 'Choose option' (Source: operator)

Switch option
  Case 1
     do something
  Case 2
     do something
  Default Case
     do something else

End of program

Depending on how you want your program to function there's a couple ways to do it. In the example @student gave, the operator will be asked for a number and then based on that number it will run everything in that specific case. If you wanted the robot to go from case to case to all the way through the switch you would want to do something along these lines:

Robot program

option = 1
Switch option
  Case 1
     do something
     option=2
  Case 2
     do something
     option=3
  Case 3
     do something
     option=4
I use this approach to control the flow of my programs easily. If you were in case one and based off of a certain condition that was met during that case, you could use an if-statement to make the decision on which case to run next. Lets say case 1 is trying to pick a part from a specific location and based on if the robot found the part or not determines what case you want the robot to go next.
if part_found= True 
    option=2
if part_found= False
   option=3
I hope that makes sense and helps out.