Javascript tricks

code :

new Date( 
    new Date().getTime()+(30 * 24*60*60*1000)
).toUTCString() ;

result :

"Fri, 29 Jul 2016 13:32:43 GMT"

code :

document.cookie = 'position.x=100; expires='+new Date( new Date().getTime()+(30 * 24*60*60*1000)).toUTCString() ;

code :

getCookie = function ( name ) {
 
    return document.cookie
                   .split(';')
                   .map(function(el) { 
                                        c = el.split('=') ; 
                                        return { 'name' : c[0], 'value' : c[1] };
                   })
                   .find(function(el) {
                                         return el.name == name ;
 
                   });
 
};

code :

position = (function ( name ) {
 
    return document.cookie.split(';')
                   .map(function(el) { 
                                        c = el.split('=') ; 
                                        return { 'name' : c[0], 'value' : c[1] };
                   })
                   .find(function(el) {
                                         return el.name == name ;
 
                   })
                   .value ;
 
})('position.x');

result :

"100"

code :

position_x = getCookie('position.x') ;

result :

Object {name: "position.x", value: "100"}