Question for easier design instead of using if/then statements

Question

Hello,

I've been working on creating an application take user input, store it in a table and printing a ship manifest.

The problem I am running into is having several text boxes where the user can insert asset #'s to ship to a specific destination.

Right now I am just using several if/then statements to first determine if the textbox is empty, and if it is not, I convert whatever was input, into an integer. 

My question is, is there an easier way to check all the textbox's to see if they are null, and if not, convert whatever is in them to an int value?  Many thanks!

Joel