Code as follows:

var content = document.getElementById("content").value;

jQuery.ajax({

type:'post',

url:'add.php',

data:"content=" + content, // value is '?'

dataType : "json",

success:function(response){

alert('success:'+response.msg);

},

error: function(msg){

alert(msg);

}

});

Code ends.

When the parameter 'content' value is '?' or '??', its content is replaced by similar content as 'jQuery1520046861610282212496_1411972375451'.

jQuery code

data = data.replace( jsre, replace );

jQuery code end.

These codes maybe need to optimize.