Pop up to ask user before leaving a page if there are unsaved chnages.

Here is the good article to implement this functionality but i was unable to do this with post back buttons in share point web part, it broke all subsequent post backs on page if user clicks "Stay on page", for Hypelinks it works perfectly. I used javascript confirm for postback buttons.

http://snippets.surfthru.com/post/Check-For-Unsaved-Changes-Before-Leaving-a-Page.aspx

Entity Framework Collection was modified; enumeration operation may not execute

http://stackoverflow.com/questions/9406088/entity-framework-collection-was-modified-enumeration-operation-may-not-execute

XML, Web Services and Special Characters

http://seroter.wordpress.com/2007/11/09/xml-web-services-and-special-characters/

http://stackoverflow.com/questions/10053656/special-characters-in-wcf-rest-post-method

jQuery Get Query String Values with Special Characters (&,')

http://www.aspdotnet-suresh.com/2013/09/jquery-get-query-string-values-with-special-characters.html

Browser Back button functionality

href="#" onClick="history.go(-1); return false;" class="btnCss"  Back

how to add/remove css class from a dom element

http://www.mzcart.com/javascript-how-to-addremove-css-class-from-a-dom-element/

Error occurred in deployment step ‘Add Solution’: A feature with ID has already been installed in this farm

http://msbuzzz.wordpress.com/2011/09/07/error-occurred-in-deployment-step-add-solution-a-feature-with-id-has-already-been-installed-in-this-farm/