1.文本框只能輸入數(shù)字代碼(小數(shù)點(diǎn)也不能輸入)
    <input onkeyup="this.value=this.value.replace(/\D/g,'')" onafterpaste="this.value=this.value.replace(/\D/g,'')">

   2.只能輸入數(shù)字,能輸小數(shù)點(diǎn).
    <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='';}">

   3.數(shù)字和小數(shù)點(diǎn)方法二
    <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}">

可以封裝成單獨(dú)的函數(shù)

 function keyPress(ob) {
            if (!ob.value.match(/^[\+\-]?\d*?\.?\d*?$/)) ob.value = ob.t_value; else ob.t_value = ob.value; if (ob.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/)) ob.o_value = ob.value;
        }
        function keyUp(ob) {
            if (!ob.value.match(/^[\+\-]?\d*?\.?\d*?$/)) ob.value = ob.t_value; else ob.t_value = ob.value; if (ob.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/)) ob.o_value = ob.value;
        }
        function onBlur(ob) {
         if(!ob.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?|\.\d*?)?$/))ob.value=ob.o_value;else{if(ob.value.match(/^\.\d+$/))ob.value=0+ob.value;if(ob.value.match(/^\.$/))ob.value=0;ob.o_value=ob.value};
        }

只需在調(diào)用，傳入this對(duì)象即可!

   4.只能輸入字母和漢字
    <input onkeyup="value=value.replace(/[\d]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[\d]/g,''))" maxlength=10 name="Numbers">

   5.只能輸入英文字母和數(shù)字,不能輸入中文
    <input onkeyup="value=value.replace(/[^\w\.\/]/ig,'')">

   6.只能輸入數(shù)字和英文
    <input onKeyUp="value=value.replace(/[^\d|chun]/g,'')">

    7.小數(shù)點(diǎn)后只能有最多兩位(數(shù)字,中文都可輸入),不能輸入字母和運(yùn)算符號(hào):
    <input onKeyPress="if((event.keyCode<48 || event.keyCode>57) && event.keyCode!=46 || /\.\d\d$/.test(value))event.returnValue=false">

    8.小數(shù)點(diǎn)后只能有最多兩位(數(shù)字,字母,中文都可輸入),可以輸入運(yùn)算符號(hào):
    <input onkeyup="this.value=this.value.replace(/^(\-)*(\d+)\.(\d\d).*$/,'$1$2.$3')">