This error is caused by output to the page before the header or session_start() functions are used.
if you read the errror carefully, it states that the out put is at line 47
(output started at /home2/ahsafety/public_html/admin/products_Insert.php:47)
line 426 is just where the header function occurs.
in this case, the probelm is a blank line betweren php code blocks.
lines 45 - 47 are:
there should not be a blank line after the closing php tag at line 45 and the opening php tag at line 47.
change that to: