/** * 扩展一个字符自动长度自动检测的函数 * @param  {[type]}   max      [description] * @param  {Function} callback [description] * @return {[type]}            [description] */jQuery.fn.maxLength = function(max, callback) {		this.each(function(){			var type 	= this.tagName.toLowerCase();			var inputType = this.type ? this.type.toLowerCase() : null;			if(type == "input" && inputType == "text" || inputType == "password") {				this.maxLength 	= max;			} else if(type == "textarea") {				this.onkeypress = function(e) {					var obj = e || event;					var keyCode = obj.keyCode;					var hasSelection = document.selection ? document.selection.createRange().text.length > 0 : this.selectionStart != this.selectionEnd;					return !(this.value.length >= max &&(keyCode > 50 || keyCode == 32 || keyCode == 0 || keyCode == 13) && !obj.ctrlKey && !obj.altKey && !hasSelection);				};				this.onkeyup = function() {					if(‘undefined‘ != typeof(callback)) {						callback(this.value.length);					}					if(this.value.length > max) {						this.value = http://www.mamicode.com/this.value.substring(0,max);>