请帮忙看看如何才能正常执行判断，目前只能执行第一条！

function validate(){
    var cprs=document.getElementsByName("rys");
    for(k=1;k<=cprs.length;k++){
        var obj = eval("select.r"+k);
        for(j=0;j<obj.length;j++)
        {
            if(obj[j].checked){
                 var SM = document.getElementById("sm").value
                 if(obj[j].value < 3 && SM== ''){
                     alert("请填写您对" + cprs[k-1].title + "评价【低分值】说明！");
                     return false;
                 }
                 if(obj[j].value > 7 && SM== ''){
                     alert("请填写您对" + cprs[k-1].title + "评价【高分值】说明！");
                     return false;
                 };
            break;
            }
        }
        if(j==obj.length){
            alert("您还未对参选人员【" + cprs[k-1].title + "】做出评价！");
            return false;
        }
    }
}