Val() Function To Make Sum In Text type Field

[Falcon88]

i have a db to recording some medical lab. results

i have some tests belongs to ( Differential WBC ) , it is :
-Lymphocyte
-MXD (mono.eosino.baso.)
-Neutrophil.

the total of this tests results must be =100.

To avoid the error in typing of results of this tests , and To alert the user when total of this results are less than 100 . i have make TEXTBOX ( DWBC ) In the main Form to brings the total By using Dsum + Val() Functions. but there are Some problems:

1.the total Does not appeared as in the Query ( DifWBC2 ). it gives the total for all patient?

2.How can I make the total Requery when typing result For any of the three tests firstly?

 

[apr pillai]

I have made some changes to your database with the addition of a Query & a Form. Added a new text box and a DLookup() function to bring the total of all tests pertaining to a particular order.

Database is attached.

 

[Falcon88]

how to make calculation for ( Differential WBC ) results only , and make msg. when the total of results of the three tests <>100