清空form表单
// 真正清空 form 表单中的内容
$("input").not(":button, :submit, :reset, :hidden").val("").removeAttr("checked").remove("selected");
$(\':input\',\'#myform\')
.not(\':button, :submit, :reset, :hidden\')
.val(\'\')
.removeAttr(\'checked\')
.removeAttr(\'selected\');