js提取字符中數字

<script language="javascript" type="text/javascript">
　　function getNum(text){
　　var value = /\d+/.exec(text);
　　//var value = text.replace(/^[0-9]/,"");
　　alert(value);
}
</script>

 

<input type="text" id="btn_getNum"/>
<input type="button" value="獲得數字" onclick="getNum(btn_getNum.value);"/>