When you have a single text box on a form, the default behavior is to submit the form when you press enter. To override this:
“If there is only one single-line text
box in the form and you press Enter in it, it submits the form. Look at
the Google or any other search engine – you are using it everyday.
I’m not sure what do you expect in your case. If you just want to
disregard the Enter hits, try this:
<form onSubmit="return false;"> <input type="text" name="selqty2"> </form>