[syslog-ng]replacing plpgsql timestamp fn calls in 7.2

[colm ennis]

hi,

a plpgsql trigger i used in 7.1 made the following use of the
timestamp function:
	insert into syslog_table values (timestamp(new.sdate, new.stime), hostid,
ciscomsgid, new.smsg);

ive had to upgrade to 7.2 and i read in the release notes that this function
is gone in 7.2:
	The timestamp() function is no longer available. Use timestamp 'string'
instead, or CAST.

how do i get this insert to work? i have no idea of the syntax required.

thanks for your help,

colm ennis