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

<input onkeyup="if(isNaN(value))execCommand('undo')"
onafterpaste="if(isNaN(value))execCommand('undo')">
<input name=txt1 onchange="if(/\D/.test(this.value)){alert('只能輸入數(shù)字');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}">

<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(/[^\w\.\/]/ig,'')">

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

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

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

<input type="text" onkeyup="this.value=this.value.replace(/[^\u4e00-\u9fa5]/g,'')">

<input type="text" onkeyup="this.value=this.value.replace(/\D/g,'')">

<input type="text" onkeyup="this.value=this.value.replace(/[^a-zA-Z]/g,'')">

<input onkeyup="value=value.replace(/[^\w\u4E00-\u9FA5]/g, '')">

<input class=input maxLength=12 size=15 name=username id="username" onKeyUp="value=value.replace(/[\W]/g,'')">

<input type="text" onkeyup="this.value=this.value.replace(/^[^!@#$%^&*()-=+]/g,'')">