I have a Grid Box With 4 columns
The first column is stockid and then specie, grade , unitcost

Questions:

1) How to validate those fields are exist or not?

I have try this:

In the grid.beforerowcolchange

With thisform.grid
idkey=.cstock.combo1.value+cspecie.combo1.value+cgrade.combo1.value
yesfound=seek(idkey,"stock",1) && (index key - stockid+specie+grade
if !(yesfound)
messagebox("Non-Existing Stock")
else
stor unitcost to .ccost.text1.value
endi
endwith

Is this code correct??