$msg =~ 
s/([^=;\"]|^)(https?:\/\/[-_.!~*'\(\)a-zA-Z0-9;\/?:\@&=+\$,%#]+)(\.png)/$1<IMG src=\"$2$3\">/gi;

$msg =~ 
s/([^=;\"]|^)(https?:\/\/[-_.!~*'\(\)a-zA-Z0-9;\/?:\@&=+\$,%#]+)(\.jpe?g)/$1<IMG src=\"$2$3\">/gi;

$msg =~ 
s/([^=;\"]|^)(https?:\/\/[-_.!~*'\(\)a-zA-Z0-9;\/?:\@&=+\$,%#]+)(\.gif)/$1<IMG src=\"$2$3\">/gi;

$msg =~ 
s/([^=;\"]|^)(https?:\/\/[-_.!~*'\(\)a-zA-Z0-9;\/?:\@&=+\$,%#]+)/$1<A href=\"$2\" target=\"_blank\">$2<\/A>/gi;