The progress bar are mostly used in user friendly interface that user can know the process status and gets the result.Here the jquery as library name blockui where is process the progress bar while requesting the server in back end. Recently i was using the ajax functionality often and embedded the progress bar gif file,after the find the block ui  jquery library  in https://malsup.github.io/jquery.blockUI.js By implementing script on top as <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>             <script src="https://malsup.github.io/jquery.blockUI.js"></script> just implementing the function like     var showProgress = function() {     $.blockUI({ message: '<img src="3.GIF" />' });     };         var hideProgress = function() {     $.unblockUI();     }; And calling the showProgress(); at beginning of ajax and implement    hideProgress(); in success

 The JavaScript is object based scripting language and so mostly the object is used access the value or function in which there are several types in it they are This are the two types that are used to access object and its properties. object literal object array try{   sr={};//object literal sd=[];//object array   rds:function pl = new Object(); pl.s="sam"; pl.d=1; pl.c="dadawd"; sr.s="samuel"; sd.s="jar"; alert(pl.s); alert(sr.s); alert(sd.s); } catch(err) {     alert(err.message); }