Nest Iif Using Instr Function

Hello,

I am trying to write a query that will search a field for a string until it discovers a comma. If there isn't a comma I want the field left as is. If there is a comma I want it to grab all strings before the comma and then take the string after the comma and flip the arrangement to another field..ie (flipname)

example if a field has [Smith, John] I want it displayed as John Smith

Here's is the code I was attempting to use below, it generates syntax errors!

SELECT Exercise1.name, Iif(Instr[name],",")=0,[Name], Mid([name],Instr([name]),+1,instr([name]),",")-1 as expr1
FROM Exercise1;

Thanks for your help!!!!!!