cannot modify headers bug?

[eluser]superfake123[/eluser]
Hello, I keep getting the following error / warning

Code:

ERROR - 2012-06-24 20:16:07 --> Severity: Warning  --> Cannot modify header information - headers already sent by (output started at /home/user/public_html/html_project/system/application/models/admin_model.php:173) /home/user/public_html/html_project/system/core/Output.php 92

line 173 of admin_model is:

Code:

imagejpeg($image,"",80);

Should I not be using that?



Thanks..