add, delete, update and add and subtract stock values..

hi there,

i am new to vb i know how to design form and i did however i really tried hard to get the values against "Location" i did in another sheet with the help of formula and it works..

but what i really want is in my sheet called "Data" i would like to add and find data in sheet "data" with the help of form via column called "Location" and find the relevant data via "location" add data via "Location" like if i add "2" parts against the location "g-1" then it will add to column called "Qty in Stock" and so on...

and i would like to get the values against "Location" to particular txtboxes that i created..
overall everything works via "location" and show up my values on form

hope i explain briefly enough...

regards
mag
sheet attached..

am i asking too much? can anyone help me please ??

i have done most of work but doesnt seems properly done.. can anyone help out if you can as i am unable to update the existing quantity in stock.. ??