try with single quotes for job, assume you have varchar column
"SELECT DISTINCT JCDISTRIBTUION FROM MST WHERE JOB='111111'"
without quotes you consider job as number type.
UPDATE:
with Text of text box
odbccmd1 = new OdbcCommand("SELECT DISTINCT JCDISTRIBTUION FROM MST WHERE JOB='"+lbljob.Text +"'", odbccon);
above will work, but you better use parameters like below
odbccmd1 = new OdbcCommand("SELECT DISTINCT JCDISTRIBTUION FROM MST WHERE JOB=?", odbccon);
odbccmd1.Parameters.AddWithValue("job", lbljob.Text);