jquery取消选择select下拉框示例代码

        全部
        aa
        bb
   
   
        全部
        a
        a
        a
        a
        a
   
   
        全部
        b
   

jQuery.fn.removeSelected = function() {
    this.val("");
};

function selectFunction(){
            if($("#sel_type").val()=="7"){
                 $("#sel_children0").show();
                 $("#sel_children1").hide();
                 $("#sel_children1").removeSelected();
             }else if($("#sel_type").val()=="8"){
                 $("#sel_children1").show();
                 $("#sel_children0").hide();
                 $("#sel_children0").removeSelected();
             }else{
                 $("#sel_children0").hide().removeSelected();
                 $("#sel_children1").hide().removeSelected();
             }
        }