>Yes, in add mode, the CurVal() and OldVal() will return null all. I find out this fact just before.:-)
>
> But, to my question, I am sure it's not in add mode.When i was test, i just changed one or more characters of the text which has existed in my textbox .When i press the entry, the problem happened.:-(
Sorry, I have no more ideas.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)