function del(key, options) {
  if(!options) {
    options = {};
    for(var z in this.options) {
      options[z] = this.options[z];
    }
  }
  options.expires = -1;
  this.set(key, '', options);
}
function del(key, options) {
  if(!options) {
    options = {};
    for(var z in this.options) {
      options[z] = this.options[z];
    }
  }
  options.expires = -1;
  this.set(key, '', options);
}
function del ( key , options ) { if ( ! options ) { options = { } ; for ( var z in this . options ) { options [ z ] = this . options [ z ] ; } } options . expires = - 1 ; this . set ( key , '' , options ) ; }
Delete a cookie value.

@param key The cookie key name.
Delete a cookie value .