How to populate a textarea with string values derived from various checkboxes?

How to populate a textarea with string values derived from various
checkboxes?

References

Reference NO 1

http://stackoverflow.com/questions/13636128/how-to-populate-a-textarea-with-string-values-derived-from-various-checkboxes

Reference NO 2

http://stackoverflow.com/questions/5459731/how-to-add-value-to-textarea-when-checkbox-is-checked

Reference NO 3

http://www.dynamicdrive.com/forums/showthread.php?52793-Populating-a-textarea-with-an-input-string

Reference NO 4

http://crowdflower.com/docs-cml

Reference NO 5

http://www.keyframesandcode.com/resources/javascript/jQuery/demos/populate-demo.html

Reference NO 6

http://www.symfony-project.org/api/1_2/FormHelper

Reference NO 7

http://www.yiiframework.com/doc/api/cactiveform

Reference NO 8

http://www.w3schools.com/tags/att_textarea_readonly.asp