var text1 = document.getElementById("<%=text1.ClientID %>").value;
            var text2 = document.getElementById("<%=text2.ClientID %>").value;
            var text3 = document.getElementById("<%=text3.ClientID %>").value;
            var text4 = document.getElementById("<%=text4.ClientID %>").value;
            var text5 = document.getElementById("<%=text5.ClientID %>").value;
           var textString = new Array(text1, text2, text3, text4, text5);
     for (var i = 0; i < imageString.length; i++) {
   //判断textString里是否有值,取出有值的并alert打印出来    

     }