File Upload Size

[viz]

hi,
I'm new to mantisbt.while uploading pdf file for product Documentation display following error
"File upload failed. This is likely because the filesize was larger than is currently allowed by this PHP installation."
Can anyone provide me accurate steps to increase File Upload Size.There are posts available on this topic but itz not working on my end.

[atrol]

As a first step run admin/check.php and have a look at the errors/warnings you get.