I have installed JavaScript Development Tools Plugin for Eclipse, but i am not able to run or debug a JavaScript Project.
I want to debug using the inbuilt Rhino Interp
Apparently you didn't create a valid javascript project. Depending on your Eclipse version, this is for Juno, go to File - New - Javascript Project.
Javascript projects don't have a "nature" associated with them that let you know in the Project Explorer. Spring, Java, or even Perl projects have this in eclipse. It's a symbol assigned to a project that lets Eclipse know what type of project it is. Java projects have a "J", Spring projects have an "S".
Which version of eclipse are you using? Install Eclipse 3.7 Java EE Version, there you could directly right click on the javascript file (.js extension) and Debug As -> Rhino JavaScript. Please see the attached image.
The Debug configuration will look as below. There will not be any browse for project, you need to browse directly javascript file as shown in below image (you can browse all the javascript files from the entire workspace).