code: function(string) {
  		// TODO split params ? &
  		YAHOO.util.Connect.asyncRequest('GET', this.options.uri+'?availabilityRequest='+string, {
  			success: function(o) {
  				var obj = lang.JSON.parse(o.responseText);
  				if(obj === "true" || !!obj){
  					this.onAvailable();
  				}
  				else if(obj === "false" || !obj){
  					this.onUnavailable();
  				}
  				else{
  					this.failure(o);
  				}
  			},
  			failure: function(o) {
  				// TODO ?
  			},
  			scope: this
  		});
  	}
docs: Perform the Ajax request