Insert multimedia message to MySQL database using PHP and Javascript -

i working on website designing conversation system (post, comment, like, etc.) social networking sites have.

i trying provide option inserting smileys along normal text content in textarea.

my questions

1. how add images smileys in textarea (which accepts text default) , when user selects 1 list or puts in symbol
2. once have textarea smileys , normal text, best way store in mysql database
3. when displaying message smileys, best way parse message database

note

i aware of developing conversation system plain text , files. not sure how add,store,display smileys.

i aware of plugins tinymce: http://www.tinymce.com/tryit/basic.php

but want know how make own.

textarea can't used display images,use contenteditable div instead.

as backend,store data in database regularly (ex: store :) directly) , maintain common table/array replace these text image/smiley each time display data.