vb.net - When I add an item to a listbox from a separate listbox, how do I find the string from the item added and search for that string within a text file? -

i working on online shopping cart application , quite new visual basic 2010. have 2 listbox's 1 current items in stock , cart. when user clicks item in stock added second list box, how find string of item added can search within text file , finds cost using array of records?

many in advance