禁止输入指定字符 有大用

下面代码 只能输入数字 一般是电话号码
<input type="text" onkeyup="value=value.replace(/\D+/g,'')" name="tel" id="tel" value="" class="intxt inputtext">

下面代码只能输数字
    <input type="text" class="d1" id="ys" name="ys"
        onkeyup=" if(event.keyCode != 37 && event.keyCode !=39 && event.keyCode !=8){(this.v=function(){this.value=this.value.replace(/[^0-9]+/,'');}).call(this)}"
        onblur="this.v();" maxlength="8" />


<input type="text" value="11位手机号码"
        style="color: #dcdcdc; padding-left: 5px;"
        onFocus="if('11位手机号码' == this.value){this.value = ''; this.style.color = '#000'};"
        onBlur="if('' == this.value){this.value = '11位手机号码'; this.style.color = '#dcdcdc'};"
        class="d2" name="tel" id="tel"
        onkeyup=" if(event.keyCode != 37 && event.keyCode !=39 && event.keyCode !=8){(this.v=function(){this.value=this.value.replace(/[^0-9]+/,'');}).call(this)}"
        onblur="this.v();" maxlength="11" />

</tr>
	<tr>
	<td colspan="2"><label>面积：
	<input class="lf-input-b" type="text" id="area" name="area" onkeyup=" if(event.keyCode != 37 && event.keyCode !=39 && event.keyCode !=8){(this.v=function(){this.value=this.value.replace(/[^0-9]+/,'');}).call(this)}" onblur="this.v();" maxlength="8" />
	</label>
	&nbsp;&nbsp;&nbsp;
	<label>预算：
	<input class="lf-input-b" type="text" id="ys" name="ys" onkeyup=" if(event.keyCode != 37 && event.keyCode !=39 && event.keyCode !=8){(this.v=function(){this.value=this.value.replace(/[^0-9]+/,'');}).call(this)}" onblur="this.v();" maxlength="8" />
	</label>
	万</td>
	</tr>
	<tr>
	<td width="136"><label>称呼：
	<input class="lf-input-c" type="text" name="realName" id="realName" value="如:陈先生" maxlength="10" onKeyDown=" return ifBusEnter(event,224);" style="color:#dcdcdc" value="如:陈先生" onFocus="if('如:陈先生' == this.value){this.value = ''; this.style.color = '#000'};"onBlur="if('' == this.value){this.value = '如:陈先生'; this.style.color = '#dcdcdc'};" />
	</label></td>
	<td rowspan="2">
	<input type="hidden" name="cid" value="0" />
	<input type="hidden" name="comMain" value="111">
	<input class="lf-btn" type="submit" value=" " />
	</td>
	</tr>
	<tr>
	<td><label>手机：
	<input class="lf-input-c" type="text" maxlength="11" onkeyup=" if(event.keyCode != 37 &amp;&amp; event.keyCode !=39 &amp;&amp; event.keyCode !=8){(this.v=function(){this.value=this.value.replace(/[^0-9]+/,'');}).call(this)}" id="tel" name="tel" value="11位手机号码" onKeyDown=" return ifBusEnter(event,224);" style="color:#dcdcdc" value="11位手机号码" onFocus="if('11位手机号码' == this.value){this.value = ''; this.style.color = '#000'};" onBlur="if('' == this.value){this.value = '11位手机号码'; this.style.color = '#dcdcdc'};"/>
	</label>
	</td>
	</tr>