You should dispose of the control using one of two methods:
1. If you created the control in the designer and know the name, you can dispose of it in this manner:
Textbox1.Dispose
2. If you create the control dynamically, you'll have to keep track of the name of the control until you want to dispose of it:
AddLabel( formName, controlName, left, top, width, height, text )
...
Control( controlName ).Dispose
Gary