操作cookie

cookie.js

function getCookie( name ) {
  var start = document.cookie.indexOf( name + "=" ),
      len = start + name.length + 1,
      end = document.cookie.indexOf( ';', len );
      
  if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) ) { 
    return null; 
  } 
  if ( start === -1 ){
    return null;
  }
  if ( end === -1 ){
    end = document.cookie.length;
  }
  return unescape( document.cookie.substring( len, end ) ); 
} 

function setCookie( name, value, expires, path, domain, secure ) { 
  var today = new Date(); 
  
  today.setTime( today.getTime() ); 
  if ( expires ) { 
    expires = expires * 1000 * 60 * 60 * 24; 
  } 
  var expires_date = new Date( today.getTime() + (expires) ); 
  document.cookie = name+'='+escape( value ) + 
    ( ( expires ) ? ';expires='+expires_date.toGMTString() : '' ) + //expires.toGMTString() 
    ( ( path ) ? ';path=' + path : '' ) + 
    ( ( domain ) ? ';domain=' + domain : '' ) + 
    ( ( secure ) ? ';secure' : '' ); 
}

function deleteCookie( name, path, domain ) { 
  if ( getCookie( name ) ){
    document.cookie = name + '=' + 
      ( ( path ) ? ';path=' + path : '') + 
      ( ( domain ) ? ';domain=' + domain : '' ) + 
      ';expires=Thu, 01-Jan-1970 00:00:01 GMT';
  }
}