When creating a plot in a GUI and when using plot3 it works fine but using surf and mesh doesn't ?

Hi, I'm creating a GUI that contains several variables x, y and z .If I used the plot3 function the graph functions properly but If I used either mesh or surf it doesn't (no errors occur).

Thanks in advance.

[Christiaan]

Dear Ahmed, could you send us your code, that we could have a look at it? Kind regards, Christiaan