Ransome,

You can perform a physical unbinding at runtime. create a subclass property called cControlSource. In the control init:

this.cControlSource = this.ControlSource
this.ControlSource = ""

In the .Refresh()
this.Value = transform( eval( this.cControlSource ) )

in the .Valid()
lnValue = your K conversion code
replace (this.cControlSource) with lnValue

>However, when I make the controlsource of the textbox to be a numeric field of the table, problem is found that I can not enter ??K format, for "K" is non-numeric;
>
>I add a line at the about valid event to solve:
>
>thisform.anothertextbox.value=this.value;
>
>in which delete the controlsource of the textbox; but make the controlsource of the anothertextbox be the original field I assign for the textbox.