Hi friends

I am working in vb.net ,there is i have a form in which i have a datagridview,& a column of checkbox in tat datagridview,when this datagridview becomes load, that checkes theb employee is present or absent if present so the check box of that perticular row must be checked true else checked false,for this i did

dim chk as checkbox

if condition that
chk.checked=true
else
chk.checked=false
end if
but it giving me a error message "object refrence not set"

please help me to solve this problem