How to populate field B with field A or field B depending if null?

[jalo23]

I can't figure out the correct syntax for the second eval statement or what else I should use instead of eval. I know the second eval statement syntax is incorrect, I am just placing it here so you can understand what I am trying to accomplish.

| eval FieldA=if(like(computername, "ABC%"), "Yes", "No")
| eval FieldB = if FieldA="No", then FieldB = FieldC, else FieldB = FieldA

Thank you!

[jalo23]

Thank you, I appreciate your super-fast response! works perfectly!

[ITWhisperer]

| eval FieldB=if(like(computername, "ABC%"), "Yes", FieldC)