check value against table?

[mohsinhq]

is it possible to check a value entered in a text box to see if it exists in a specific table?

all help appreciated..

 

[KenHigg]

Use dlookup()

???
ken

 

[mohsinhq]

ive had a look in help and it says that dlookup returns a value to the form..

i just want it to check the value in my textbox (ShipNo) against the value in the query (BDPE_LOV_Data) and the field (ROUTE_ID)

i tried putting this into the control of the text box :

=DLookUp("[ROUTE_ID]","BDPE_LOV_Data")

without any luck. it wont let me enter a value in the text box

??

 

[KenHigg]

a. Sounds like the control source should be set back to ShipNo?

b. In the before update event for the ShipNo text box, would something like the following work:

if not isnull(dllookup("[rout_id]","BDPE_LOV_Data", "[rout_id] = " & me!shipNo)
do some stuff
else
msgbog "Ship no / route id problem"
docmd.cancelevent
end if



???
kh