function order_check(){
    var _num = $("input[name='txt_num']").val();
    var _tel = $("input[name='txt_tel']").val();
    var _address = $("input[name='txt_address']").val();
    
    var strCheck=/^[0-9]*[1-9][0-9]*$/;//必须是数字
    
    var checknum = false;
    var checktel = false;
    var checkaddress = false;
    
    _num = trim(_num);
    if(_num == ""){
        alert("请填写订购数量！");
    } else {
        if(!strCheck.test(_num)){
            alert("订购数量必须为数字！");
        } else {
            checknum = true;
        }
    }
    
    _tel = trim(_tel);
    if(_tel == ""){
        alert("请填写电话号码！");
    } else {
        checktel = true;
    }
    
    _address = trim(_address);
    if(_address == ""){
        alert("请填写地址！");
    } else {
        checkaddress = true;
    }
    
    if(checknum && checkaddress && checktel){
        return true;
    } else {
        return false;
    }
};

//去除全部空格
function trim(str){
    str = str.replace(/\s+/g,"");
    return str;
};