alert Message messing up

[sdbdgwood]

I am having a problem with a alert message popping up when it doesnt need to. Also i can not delete it from the code because it breaks the code. if you guys could look at this it would help great.
http://www.buychemcrest.com/Jacked/quote.html

The alert message pops up even though it works. meaning that it finds the part number and adds the price to the right column but the alert message still pops up. The problem i am having is in the first row only. That is where it has the auto complete drop down.

to test it go the first row and push any letter when the part number comes up click that and it will put it in the field. then the the cost will add into the third column. that part is right but the error message still pops up.

But if you put that same part number in the second row then it works 100%.