JavaScript 验证 : Block special characters From input text box when click on submit

Question

如何通过编辑以下代码来限制在文本框 (txt_edition) 中输入特殊字符以进行验证？我只想输入数字。

<script>
function validateForm() 
{
var x = document.forms["frm_bokAdd"]["txt_edition"].value;
if (x==null || x=="") 
{
    alert("Edition must be filled out");
    return false;
} 
</script>

下面是我的表格

<form  name="frm_bokAdd" action ="#"  method="post" onsubmit="return validateForm()" >
<table border="0" align="center">
    <tr><td> <input type="text" name="txt_edition" ></td></tr>
    <tr><td> <input type="submit" name="bookIns_submit" value="Add"></td></tr>
</table>
</form>

Answer 1

可以用这个

HTML

<input type="text" onkeypress="return isNumber(event)" >

JS(在正文末尾)

function isNumber(evt) {
    var charCode = (evt.which) ? evt.which : event.keyCode
    if (charCode > 31 && (charCode < 48 || charCode > 57)) {
        return false;
    }
    return true;
}

<强> DEMO is Here