Adding two different Event triggers for the same table

[sushaanth srirangapathi]

I creates a "Before Insert" and "before Update" trigger on a table.But only one trigger is firing.To be more specific Only the last added trigger is firing. Example : table has three columns (a,B,c) and A is the primary Key column. I have to write trigger which will auto populate A using values in B and C. So i need both "before insert" and "before update" triggers. Can you guys give me help on this. I'm using MySQL workbench.