for loop become to while loop

this is my code , but it's for loop, I want to become to "while loop"

How to do?

pleas teach me , thank you!

for im=idxip(a):idxip(a+1)

           subplot(1,1,1);        
           imshow(uint8(xi(:,:,:,im)));  
           title('video','Fontsize',22);
            %pause(1);

           drawnow;                        
  end

Answer 1

[Ilham Hardy]

doc while

Answer 2

[Azzi Abdelmalek]

          im=idxip(a)
          while im<=idxip(a+1)
            %----your code----------------
            subplot(1,1,1);        
            imshow(uint8(xi(:,:,:,im)));  
            title('video','Fontsize',22);
            %pause(1);
            drawnow;
            %------------------------------
            im=im+1                        
          end

% while the condition is checked, the program will redo the loop