文本框限制

1上面的文本框只能输入数字代码(小数点也不能输入):

CODE:
<input  onkeyup="this.value=this.value.replace(//D/g,'')"  onafterpaste="this.value=this.value.replace(//D/g,'')">
<input  onkeyup="this.value=this.value.replace(//D/g,'')"  onafterpaste="this.value=this.value.replace(//D/g,'')">

2只能输入数字,能输小数点.(注意汉字.用输入法和复制上面三个是有区别的在这里)

CODE:

<input  onkeyup="if(isNaN(value))execCommand('undo')"  onafterpaste="if(isNaN(value))execCommand('undo')">
<input  onkeyup="if(isNaN(value))execCommand('undo')"  onafterpaste="if(isNaN(value))execCommand('undo')">

CODE:
<input  name=txt1  onchange="if(//D/.test(this.value)){alert('只能输入数字');this.value='';}">
<input  name=txt1  onchange="if(//D/.test(this.value)){alert('只能输入数字');this.value='';}">

CODE:
<input type=text t_value="" o_value="" onkeypress="if(!this.value.match(/^[/+/-]?/d*?/.?/d*?$/))this.value=this.t_value;else this.t_value=this.value;if(this.value.match(/^(?:[/+/-]?/d+(?:/./d+)?)?$/))this.o_value=this.value" onkeyup="if(!this.value.match(/^[/+/-]?/d*?/.?/d*?$/))this.value=this.t_value;else this.t_value=this.value;if(this.value.match(/^(?:[/+/-]?/d+(?:/./d+)?)?$/))this.o_value=this.value" onblur="if(!this.value.match(/^(?:[/+/-]?/d+(?:/./d+)?|/./d*?)?$/))this.value=this.o_value;else{if(this.value.match(/^/./d+$/))this.value=0+this.value;if(this.value.match(/^/.$/))this.value=0;this.o_value=this.value}">
<input type=text t_value="" o_value="" onkeypress="if(!this.value.match(/^[/+/-]?/d*?/.?/d*?$/))this.value=this.t_value;else this.t_value=this.value;if(this.value.match(/^(?:[/+/-]?/d+(?:/./d+)?)?$/))this.o_value=this.value" onkeyup="if(!this.value.match(/^[/+/-]?/d*?/.?/d*?$/))this.value=this.t_value;else this.t_value=this.value;if(this.value.match(/^(?:[/+/-]?/d+(?:/./d+)?)?$/))this.o_value=this.value" onblur="if(!this.value.match(/^(?:[/+/-]?/d+(?:/./d+)?|/./d*?)?$/))this.value=this.o_value;else{if(this.value.match(/^/./d+$/))this.value=0+this.value;if(this.value.match(/^/.$/))this.value=0;this.o_value=this.value}">

3只能输入字母和汉字

CODE:
<input onkeyup="value=value.replace(/[/d]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[/d]/g,''))" maxlength=10 name="Numbers">
<input onkeyup="value=value.replace(/[/d]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[/d]/g,''))" maxlength=10 name="Numbers">

4只能输入英文字母和数字,不能输入中文

CODE:
<input onkeyup="value=value.replace(/[^/w/.//]/ig,'')">
<input onkeyup="value=value.replace(/[^/w/.//]/ig,'')">

5只能输入数字和英文chun

CODE:
<input onKeyUp="value=value.replace(/[^/d|chun]/g,'')">
<input onKeyUp="value=value.replace(/[^/d|chun]/g,'')">

6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:

CODE:
<input onKeyPress="if((event.keyCode<48 || event.keyCode>57) && event.keyCode!=46 || //./d/d$/.test(value))event.returnValue=false">
<input onKeyPress="if((event.keyCode<48 || event.keyCode>57) && event.keyCode!=46 || //./d/d$/.test(value))event.returnValue=false">

7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

CODE:
<input onkeyup="this.value=this.value.replace(/^(/-)*(/d+)/.(/d/d).*$/,'$1$2.$3')">
<input onkeyup="this.value=this.value.replace(/^(/-)*(/d+)/.(/d/d).*$/,'$1$2.$3')">

既禁止数字以外的键值输入，又禁止激活输入法，同时通过正则表达式将数字以外的值替换成空串。

Html代码 

1. <input type="text" style="ime-mode:disabled;" onKeyPress="if(event.keyCode < 48 || event.keyCode > 57) event.returnValue = false;" onKeyUp="this.value=this.value.replace(/\D/g,'')" />