IF(ISNA(VLOOKUP.. returns 0 instead of empty cell

I have this function on my sheet, cell should be empty "" or return "x" from another sheet. Problem is, it doesn't. It works if you don't touch anything, but i do have to.

=IF(ISNA(VLOOKUP(A1,table,2,FALSE)),"",VLOOKUP(A1,table,2,FALSE))

Sheet1 has the formula where i want the string "x" or empty cell to be, data to compare on sheet2.

data on sheet2
20201 x
20049
21677 x

on sheet2 the data changes, and sometimes there is an "x" and sometimes no. If i remove the x from data, then the formula returns 0 instead of empty. Why?

this works PaulM100, thank you!

A slight variation on Richard's formula:

=IFERROR(VLOOKUP(A1,table,2,FALSE)&"","")

which will ensure that a blank in the table will be returned as a blank and not zero.

Hope this helps.

Pete