//设置焦点相关---begin
//用法：$("#txtInput").val("你好").focusEnd();
$.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 () {
 if (this.val() != undefined) {
 this.setCursorPosition(this.val().length);
 }
}
//设置焦点相关---end