Error in IF formula with space

Hi Friends,

I have a 'Input Column', where user will enter the data. The column can have following three scenario
1) Blank,
2) Numeric with 'Hyphen' (example : 603160-Communications-Other)
3) Numeric with no 'Hyphen' (example : 603160)

I am using formula =IF(B4="","",TRIM((LEFT(B4,FIND("-",B4)-1)))). In this cell B4 has the text/value. The formula works well for 1st and 2nd. But I get #VALUE! in the 3rd scenario.

Kindly advice how to correct the formula.

Thanks

Thanks Trevor. This solution works!!