I would use a Combo Drop down box to list the Job Numbers and Jobs in the second column, the combo jumps to the job number as the user inputs the number, or they can just select one from the list.
You then just need some simple vba in the "After Update" event procedure of the combo box.
me.textboxname = mecomboxname.column(1)
Where textboxname is the actual name of your text box and mecomboxname is the name of your combo.