<input type="text" id="d1" onblur=" chkNumber(this)"/>

<script type=”text/javascript” />

function chkNumber(eleText)

       {

              var value =eleText.value;

              var len =value.length;

              for(vari=0;i<len;i++)

              {

                     if(value.charAt(i)>"9"|| value.charAt(i)<"0")

                     {

                            alert("含有非数字字符");

                            eleText.focus();

                            break;

                     }

              }

       }

</script>