Ajax Object - 12030 Loop Fix?

Question

Here are 3 methods which handle my ajax calls.

I loop until pass b.c. I've had problems with the Ajax Object working as expected. This is noted here

/**
 *    Ajax
 */

var Ajax = ( function () 
{
    var Ajax = function (element) 
    {
        this.object = this.create();
    };
    Ajax.prototype.create = function() 
    {
        var request;
        try
        {
            request = new window.XMLHttpRequest();
        }
        catch( error )
        {
            try 
            {
                request = new window.ActiveXObject( "Msxml2.XMLHTTP" );
            }
            catch( error )
            {
                try
                {
                    request = new window.ActiveXObject( "Microsoft.XMLHTTP" );
                }
                catch( error )
                {
                    request = false;
                }
            }
        }
        return request;
    };
    Ajax.prototype.use = function( param, ajax_func )
    {
        var GATEWAY = 'class.ControlEntry.php';  
        var self = this;
        this.object.open( "POST", GATEWAY, true );
        this.object.setRequestHeader( "Content-type", "application/x-www-form-urlencoded" );
        this.object.setRequestHeader( "Content-length", param.length );
        this.object.setRequestHeader( "Connection", "close" );
        this.object.onreadystatechange = function()
        {
            if( this.readyState === 4 )
            {
                if( this.status === 200 )
                {
                    ajax_func( this.responseText );
                    return true;
                }
                else
                {
                    self.invoke( param, ajax_func );
                    return false;
                }
            }
        };
        this.object.send( param );
        return true;
    };
    Ajax.prototype.invoke = function( param, ajax_func )
    {
        var state = false,
            count = 1;
        while( state === false && count <= 5 )
        {
            if( count !== 1 )
            {
                alert( 'Ajax Object Use Failed | Try Again ');
            }
            state = this.use( param, ajax_func );
            count++;
        }
        return state;
    };
    return Ajax;
} () );

Answer 1

This is the real bad practice.

1. The Ajax is Asynchronous, you never know how the response will back.
2. Javascript is the single thread language, so that means in one time period just can run one function. in your repeatUseAjax function, you try to loop send ajax. the result will be you will send 5 times ajax call every time when the ajax response failure.And you will never know when the response suceess. what about first failure other success? what about always failure?loop forever?