Check textbox values on the front-end before submitting to server-side logic

Check textbox values on the front-end before submitting to server-side logic

Room,
 
Hi.  I am new to jQuery, and learning more about Js by doing.  I can hand-code HTML and CSS very well and understand OOP effectively.  However, troubleshooting complex Javascript code combined with jQuery is a challenge to me, but I really want to learn.  I am using Windows XP Professional and IE 8, FF 3.6.
 
That said, I will attempt to explain what I need to do. 
 
Description:
The page is being written on the fly.  There is a server-side function that cannot accept zero quantity values. The request here (in this code) is being submitted with a zero quantity. I need to test on the front-end that the value in the quantity text box is not sending the request to the server if there is a "0" value in the quantity textbox. 
 
The array is set up as follows:
catEntry_1
catEntry_2
catEntry_3
catEntry_4
and so on....



 
Please give special attention to function beginning on line 230.  In between line 232 and 233, I have inserted some code to check/change a value, but this is not enough needed to do what I stated in my description above. 
 
Could someone help me out with this?
    Thanks in advance.
    Noah