sql - Access query criteria "If Option 3, return null" -

sql - Access query criteria "If Option 3, return null" -

i have access query looks @ form see of 3 radio buttons (in grouping called frmstatus) selected. if first selected, iif returns "true", , if sec selected, returns "false", if 3rd selected, want iif homecoming absolutely nil criteria is, in effect, empty.

right now, criteria:

iif([forms]![sp_search_criteria]![frmstatus]=3,like "*",iif([forms]![sp_search_criteria]![frmstatus]=1,true,false))

with sql (disregard date() part -- that's searching age):

where ((((date()-[dob])/365.25)>=[forms]![sp_search_criteria]![txtminage] , ((date()-[dob])/365.25)<[forms]![sp_search_criteria]![txtmaxage]) , ((standardizedpatients.active)=iif([forms]![sp_search_criteria]![frmstatus]=3,(standardizedpatients.active) "*",iif([forms]![sp_search_criteria]![frmstatus]=1,true,false))))

options 1 , 2 work fine... can't seem alternative 3 work @ all.

so, question this: what can set in iif within query criteria search without criteria?

i got work -- did remove "like "*"" part, looks this:

where ((((date()-[dob])/365.25)>=[forms]![sp_search_criteria]![txtminage] , ((date()-[dob])/365.25)<[forms]![sp_search_criteria]![txtmaxage]) , ((standardizedpatients.active)=iif([forms]![sp_search_criteria]![frmstatus]=3,(standardizedpatients.active),iif([forms]![sp_search_criteria]![frmstatus]=1,true,false))))

sql ms-access ms-access-2010