不能设置 验证码数字的个数啊

[HuZai]

CAP.prototype._init = function(args){
if(arguments.length<1) return;//如果不传参数，则全部使用默认值

if(typeof arguments[0] === 'object'){//如果传递了对象，则替换默认值
	var obj = arguments[0];
	this.width = obj.width || this.width;
	this.height = obj.height || this.height;
	this.offset = obj.offset || this.offset;
    this.quality = obj.quality || this.quality;
	this.generate = obj.generate || null;
	this.fontsize = obj.fontsize || this.fontsize;
	return;
}

this._text_len = 6;//这个不能改 啊