jsonp.js

window.jsonpCbs = { };

var jsonp = function( o ) {
    var key = 'cb' + Math.floor( Math.random( ) * 100000 );
    var sep = o.uri.indexOf( '?' ) < 0 ? '?' : '&';
 
    var scriptEl = document.createElement( 'script' );
    scriptEl.setAttribute( 'type' , 'text/javascript' );
    scriptEl.setAttribute( 'src' , [ o.uri , sep , o.jsonp || 'jsonp' , '=jsonpCbs.' , key ].join( '' ) );
 
    var sto;

    var clear = function( ) {
        delete window.jsonpCbs[key];
 
        scriptEl.parentNode.removeChild( scriptEl );//Seppuku
 
        clearTimeout( sto );
    };

    var errorCb = function( err ) {
        return function( ) {
            o.cb.call( null , err );
 
            clear( );
        }
    };
 
    var sto = setTimeout( errorCb({
        error : 'Request Timeout' ,
        code  : 408
    }) , o.timeout || 4000 );

    scriptEl.onerror = errorCb({
        error : 'Bad Request' ,
        code  : 400
    });
 
    window.jsonpCbs[ key ] = function( ) {
        o.cb.apply( null , arguments );
 
        clear( );
    };
 
    document.head.appendChild( scriptEl );
};