How to formulate a cell based on the table of contribution

Hi

Need help to correct my formula. I try using this formula in order to plot the contribution of the employer based on the salary of an employee:
=INDEX(contri table!$F$5:$F$33,MATCH($A4,TRIM(LEFT(contri table!$B$5:$B$33,FIND("-",contri table!$B$5:$B$33)-1))*1,1)) but it always gives me a #N/A result, what seems to be problem? Hope you could enlighten me bout this.


Thank you.