Java script error in OOB Webparts Modification.

In a OOB webpart user gets an error onclick of edit.This error occures just becasue of the below reasons.This type of issues are due to conflicting IDs in the auto generated code from copy/pasting into content editor web part editor from other sources such as MS Word.
We can avoid this type of issues by formatting using Rich Text Editor from the content editor web part rather than copying and pasting from other sources.

The below steps may be useful in creating contents:

1) Put page in edit mode

2) Edit the content of the content editor web part by selecting the 'modify web part' drop down menu.

3) Select the Rich Text Editor and copy the text if you do not want to lose it.

4) Select Source Editor button, this opens the HTML source code for this Web Part 5) Remove the source code if our source code had a conflicting ID,auto generated code.

6) Update web part and make sure source code does not have auto generated code, or just add a new content editor web part

How to remove Bad web parts from the Share point site

To remove bad webparts from the site.Append ?Contents=1 to the Web Part Page’s URL. For example, http://gardenco/default.aspx?contents=1. The Web Part Maintenance Page is displayed and from there you can delete the offending Web Part. Using this page the above mentioned erronous webpart can be removed.