mysql error(ambiguos column)

hi everyone i'm new to this forum and i've been trying to solve this problem for some days now .i trying to retrieve data from a join query based on certain conditons but keep getting an mysql error. the query is shown below:
select c.Sender,c.Subject,c.Message,c.date,c.Time,m.Recip ient
from co_messages as c,mess_link as u,mess_Recipient as m
where c.id=u.co_id and m.id=u.id and Sender='gkanu';

Query Failed: Column 'Sender' in where clause is ambiguous

The db doesn't know what table to look for Sender in -- you need to label it with the alias of the proper table like the other column references:

thanks i sorted that out.