<input type="text" name="page" id="page" onkeypress="return inputIsNum(event)" />
<script>
//判断输入是否为数字
function inputIsNum(e){
e = window.event||e;
var code = e.keyCode || e.which;
if(code>=48&&code<=57)
return code;
else
return false;
}
</script>