Continous Forms/text boxes

[mercury]

Hi again

In my database im using continous forms and i want to know if there is a way i could increase the value in a text box by other values in other text. Is there anyway i could do this without using a button.

Thanks

 

[KenHigg]

Sorry - A little more info needed...

 

[mercury]

Ok my database is dealing with stock and what i would like to do is when a person increases the stock they would enter the value in the Amount textbox and this value would be added on to a text box called "Instock". But the thing is im using a continuos form formatt and i would like to know how you could get this done without using a button

 

[KenHigg]

I'm afraid I've been banned from inventory database questions...