Json

Hai all,

I`m doing simple offline chat application., i have stored data in json object and persist to a json file,
i do not know how to retrieve the json object from .js file

this is my code :

<!DOCTYPE html>

<title></title>
	
		
<style type="text/css">
body{
		width:100%;
		background-color:#000;
	}
#main_container
	{
	width:95%;
	height:560px;
	background-color:#fff;
	
	}
#left_container
	{
	width:70%;
	height:500px;
	margin:5px 0px 5px 5px;
	float:left;
	background-color:#ddd;
	}
#right_container
	{
	width:28%;
	height:550px;
	margin:5px 5px 5px 0px;
	float:right;
	background-color:#ddd;	
	}
#taComment
	{
		margin-top:15px;
		width:90%;		
		height:380px;
		border:1px solid gray;
		max-width:90%;
		max-height:400px;
		resize:none;
	}
.shadow 
   {
      -moz-box-shadow: 5px 5px 0px 0px #bbb;
      -webkit-box-shadow: 5px 5px 0px 0px #bbb;
      box-shadow: 5px 5px 0px 0px #bbb;
   }

.txt_border
    {
	 	border:1px solid gray;
		resize:none;        
	}
#img_adj
	{
	 	margin-top:15px;
	}
		
#title
	{
	padding-top:15px;
	height:40px;
	font-size:1.5em;
	background-color:#000;
	color:pink;
	font-weight:bold;
	}
.color1
	{
	 color:blue;
	 width:90%;
	 height:20px;
	}
.color2
	{
	 color:red;
	 width:90%;
	 height:50px;
	}   
	
.button {
	display: inline-block;
	outline: none;
	cursor: pointer;
	text-align: center;
	text-decoration: none;
	font: 12px/100% Arial, Helvetica, sans-serif;
	padding: .4em 1em .45em;
	text-shadow: 0 1px 1px rgba(0,0,0,.3);
	-webkit-border-radius: .5em; 
	-moz-border-radius: .5em;
	border-radius: .5em;
	-webkit-box-shadow: 0 1px 2px rgba(0,0,0,.2);
	-moz-box-shadow: 0 1px 2px rgba(0,0,0,.2);
	box-shadow: 0 1px 2px rgba(0,0,0,.2);
}

.button:hover {
	text-decoration: none;
}
.button:active {
	position: relative;
	top: 1px;
}

.blue {
	color: #fff;
	font-weight:bold;
	font-size:11px;
	border: solid 2px #fff;
	background: #2981ad;
	background: -webkit-gradient(linear, left top, left bottom, from(#4aaacd), to(#2981ad));
	background: -moz-linear-gradient(top,  #4aaacd,  #2981ad);
	filter:  progid:DXImageTransform.Microsoft.gradient(startColorstr='#4aaacd', endColorstr='#2981ad');
}

</style>

beforeSend: function(x) 
		 {
            if (x && x.overrideMimeType) 
			{
               x.overrideMimeType("application/json;charset=UTF-8");
            }
         },
         success: function(result) 
		 {
	        alert(result);
         }
	     });

alert('after of storeTOJSON : '+jsonCurrComments.Comments);
	}
   function restoreComment()
   {
       alert('onload from body............!!!!!!!');
       getContent();
	   //getTOJSON();
       //$('#taComment').val(localStorage.getItem('comment'));
	   var objControl=document.forms["frmComment"].elements["taComment"];
       objControl.scrollTop = objControl.scrollHeight;	   	        
   }
   
   function getContent()
   {  
		 $.get("get_json.php",function(data)
	  	 {
 			localStorage.setItem('comment',data);
			alert(data); 
			$('#taComment').val(data);			 
			alert("get old comment : "+data);

});					
	}
	
	/*function setContent(data)
	{	
		$.post("put_json.php",{"notes":data});
        alert('data from file '+data);	
		arrComments=new Array();
		arrComments.push(data);
	}	*/
	function clearControls()
	{
	  	  $('#txtComment').val("");
		  $('#txtName').val("");   	 
    }   
	function validate(strComment,strName)
	{
	     var foo=true;
	     var iChars = "!@#$%^&*()+=-[]\\\';,./{}|\":<>?";
	     if(strComment=="" && strName=="")
	     {
		     alert('Name and Comment should not be empty.');
			 //$('input:text:txtName').focus();
			 document.getElementById('txtName').focus();
		     foo=false;			 
		  }
		  else if(strComment=="")
		  {
		     alert('Comment should not be empty.');
			 //$('input:text:txtComment').focus();
			 document.getElementById('txtComment').focus();
		     foo=false;
		  }
		  else if(strName=="")
		  {
		     alert('Name should not be empty.');
			 $('#txtName').focus();
		     foo=false;
		  }
		  else if($('#txtName').val().length>0)
		  { 
    		  for (var i = 0; i < $('#txtName').length; i++) 
    		  {
        	     if (iChars.indexOf($('#txtName').val().charAt(i)) != -1) 
    		     {				
    			 	alert("please enter the valid name...!!!");
    			    $('#txtName').focus();
    		  	    foo=false;   	
    		     }
    	      }	
		  }	 
		  return foo; 
	}

//window.setInterval(restoreComment,1000);
   	   
	</script>
    
	
  </head>
  <body onload="restoreComment()">
  <form id='frmComment' onSubmit="storeCom()">
  <div align="center">
  	   <div id="main_container">
  	   		<div id="left_container">
	   			 <div id='img_adj'>
				 <embed src="63.html" height="450" width="710"/>
			         <p id='title'>Offline Chat Application</p>
				 </div>			
	         </div>

</body>
</html>

if i`m restore the old contents also be json object only.please give me a suggestions to overcome this.

Ajax