通过Javascript控制文本框中只输入数字

   function goto_page(e){       var keynumber; //键盘ASCII码       if(window.event){           //浏览器为IE           keynumber = e.keyCode;       }       if(e.which){           //浏览器为Firefox、Opera           keynumber = e.which;       }       if(keynumber < 48 || keynumber > 105 || (keynumber > 57 && keynumber < 96)){           document.getElementById("pageno").value="1";       }   }

<input type="text" id="pageno" onkeydown="goto_page(e)" onkeyup="goto_page(e)"></input>