1.文本框只能输入数字代码(小数点也不能输入)
<input οnkeyup="=.replace(/\D/g,'')" onafterpaste="=.replace(/\D/g,'')">

2.只能输入数字,能输小数点.
<input οnkeyup="if(isNaN(value))execCommand('undo')" onafterpaste="if(isNaN(value))execCommand('undo')">
<input name=txt1 οnchange="if(/\D/.test()){alert('只能输入数字');='';}">

3.数字和小数点方法二
<input type=text t_value="" o_value="" οnkeypress="if(!.match(/^[\+\-]?\d*?\.?\d*?$/))=this.t_value;else this.t_value=;if(.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/))this.o_value=" οnkeyup="if(!.match(/^[\+\-]?\d*?\.?\d*?$/))=this.t_value;else this.t_value=;if(.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/))this.o_value=" οnblur="if(!.match(/^(?:[\+\-]?\d+(?:\.\d+)?|\.\d*?)?$/))=this.o_value;else{if(.match(/^\.\d+$/))=0+;if(.match(/^\.$/))=0;this.o_value=}">

4.只能输入字母和汉字
<input οnkeyup="value=(/[\d]/g,'') "onbeforepaste="('text',('text').replace(/[\d]/g,''))" maxlength=10 name="Numbers">

5.只能输入英文字母和数字,不能输入中文
<input οnkeyup="value=(/[^\w\.\/]/ig,'')">

6.只能输入数字和英文<font color="Red">chun</font>
<input onKeyUp="value=(/[^\d|chun]/g,'')">

7.小数点后只能有最多两位(数字,中文都可输入),不能输入字母和运算符号:
<input onKeyPress="if((<48 || >57) && !=46 || /\.\d\d$/.test(value))=false">

8.小数点后只能有最多两位(数字,字母,中文都可输入),可以输入运算符号:
<input οnkeyup="=.replace(/^(\-)*(\d+)\.(\d\d).*$/,'$1$2.$3')">

======================文本框只能输入数字及小数点=========================

<li class="searchbox_name">主设备：</li>
                        <li class="searchbox_box">
                            <asp:TextBox ID="txtMain_Mate" runat="server"></asp:TextBox>万 </li>
                        <asp:FilteredTextBoxExtender ID="FilteredTextBoxExtender1" runat="server" FilterType="Custom"
                            ValidChars="012345689." TargetControlID="txtMain_Mate">