multiple scenarios in an if,iserror,vlookup formula.....

=IF(OR(((((ISERROR(VLOOKUP(K12,'Clock#'!A:B,2,FALSE))))=TRUE)),OR(K12=""),OR(VLOOKUP(K12,'Clock#'!A:B,2,FALSE))),("False"),(""))
i am trying to vlookup a clock number out of a list with name in 2nd column. i want it to say 'false #' if the number entered into k12 isnt in the list on 'Clock# A:B', but stay empty when nothing is entered in k12, AND return the name adjacent if relevant......can you help me ? it currently says '#VALUE!' but no mathmatical steps are there :s