A = <INPUT   Type=TEXT   Name=EditA   Value="3"   > &nbsp; &nbsp;

B = <INPUT   Type=TEXT   Name=EditB   Value="4"   ><BR><BR>

<INPUT   Type=TEXT   Name=EditResult   > &nbsp;

<INPUT   Type=BUTTON   Value=" A - B "
   OnClick="VBSCRIPT:EditResult.Value=CDbl(EditA.Value)-CDbl(EditB.Value)"
   >