[Axapta-Knowledge-Village] Container and unbounded string fields error

[ricardodegouveia]

Hi how do you fix the "Container and unbounded string(text)fields are 
not allowed in a WHERE expression" error?

I created a method and pass in parameters:

1) void method1(str _param1,str _param2, str _param3)
2){
3)  HRMVirtualNetworkTable hrmVirtualNetworkTable;
4)    ;
5)  select firstOnly forUpdate hrmVirtualNetworkTable
6)    where hrmVirtualNetworkTable.reference == _param1;
7)}

i get the error on line (6). and i dont know why?

can anyone help please im desperate.
Thanking you in advance.
Ricardo