script to search a file

hi all
i have a requirement to write a script which will serach a file in a particuar location for 3 hours from the time when the script is run.if during this period the file arrives in a particular location then this will transmit the file to a other server.please help me writing the script which will search the file in a particular location for 3 hrs.

quick idea came on my mind. There could be better solution.

while true
do
search whether file exist or not
if exist, send to destination and exit from the loop
else sleep for a minute and continue the loop until the counter reach 180
done