Lock a column in script while working with multiple tables with same column names

[#1]

I have three tables I am working with in my JSL. I am calling these dt1, dt2, dt3. 

dt1 has the columns A, B, C, D

dt2 has the columns B, X, Y, Z

dt3 has the columns D, Q, R, S

I want to lock B in table dt2. How do I do that? The usual ":B << lock (1)" script is locking B in dt1. 

[#2 · Accepted solution]

If you don't tell JMP which table to use, it uses current data table -> use more robust method of referencing to your column (add datatable reference). Column(dtref, colname) is my preferred method

Names Default To Here(1);
dt = Open("$SAMPLE_DATA/Big Class.jmp");
Column(dt, "Age") << Lock(1);

You could also use dt:Age

Names Default To Here(1);
dt = Open("$SAMPLE_DATA/Big Class.jmp");
dt:Age << Lock(1);

Edit:

From Scripting Guide check out Scripting Guide > JSL Building Blocks > Rules for Name Resolution > Scoping Operators