jQuery设置聚焦并使光标位置在文字最后的实现方法

$.fn.setCursorPosition = function(position) {	if (this.lengh == 0)		return this;	return $(this).setSelection(position, position);};$.fn.setSelection = function(selectionStart, selectionEnd) {	if (this.lengh == 0)		return this;	input = this[0];	if (input.createTextRange) {		var range = input.createTextRange();		range.collapse(true);		range.moveEnd('character', selectionEnd);		range.moveStart('character', selectionStart);		range.select();	} else if (input.setSelectionRange) {		input.focus();		input.setSelectionRange(selectionStart, selectionEnd);	}	return this;};$.fn.focusEnd = function() {	this.setCursorPosition(this.val().length);};