Hey,

I need to restrict the user from entrying any duplicate values in the database. I have a Members Object. It has an auto text field and and a member name lookup field which is related to User Object. I don't want any one to pick and add any user from the look field which is already there in my Members list. 

So I have not been able to add this rule to my object. I don't want to use any triggeers for this. Validation rules had not enabled to me do this so far. I also tried to add a filter criteria to the lookup filter. It is not letting me compare the values of Current Lookup Member Name field to Current Record Member Name field. 

Could anyone please suggest any workaround for this ?