Hi

iam using sugarcrm(5.0)
i've created one custom chkbox field called priamary_contact_c in contacs module .
my requirement is:
if i've an account..under tht accont there r 4 contacts
one contact only should be primary..
if one contct chk box is chked..thn the other contacts doesn't allow to chk the primary contact

any one suggest me ,how to do this

thx
Arun