<input type=”text” name=”textfield” onKeyPress=”javascript:alert(event.keyCode);return flase”>
1.文本框只能輸入數(shù)字代碼(小數(shù)點也不能輸入)
<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.
<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(/^.$/))this.value=0;this.o_value=this.value}”>
4.只能輸入字母和漢字
<input onkeyup=”value=value.replace(/[d]/g,”) “onbeforepaste=”clipboardData.setData(‘text’,clipboardData.getData(‘text’).replace(/[d]/g,”))” maxlength=10 name=”Numbers”>
5.只能輸入英文字母和數(shù)字,不能輸入中文
<input onkeyup=”value=value.replace(/[^w./]/ig,”)”>
6.只能輸入數(shù)字和英文<font color=”Red”>chun</font>
<input onKeyUp=”value=value.replace(/[^d|chun]/g,”)”>
7.小數(shù)點后只能有最多兩位(數(shù)字,中文都可輸入),不能輸入字母和運算符號:
<input onKeyPress=”if((event.keyCode<48 || event.keyCode>57) && event.keyCode!=46 || /.dd$/.test(value))event.returnValue=false”>
8.小數(shù)點后只能有最多兩位(數(shù)字,字母,中文都可輸入),可以輸入運算符號:
<input onkeyup=”this.value=this.value.replace(/^(-)*(d+).(dd).*$/,’$1$2.$3′)”>

<input onkeyup=”value=value.replace(/[^d.]/g,”)”>
<input type=text onkeypress=”return event.keyCode>=65″ style=”ime-mode:disabled”>

<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=”this.value=this.value.replace(/D/g,”)” onafterpaste=”this.value=this.value.replace(/D/g,”)”>
or
<input name=txt1 onchange=”if(/D/.test(this.value)){alert(‘只能輸入數(shù)字’);this.value=”;}”>
or
<input onkeyup=”if(isNaN(value))execCommand(‘undo’)” onafterpaste=”if(isNaN(value))execCommand(‘undo’)”>

限制文本框只能輸入數(shù)字包括小數(shù)點
<input onkeyup=”value=value.replace(/[^d.]/g,”)”>
有關正則表達式 1.只能輸入數(shù)字和英文的： <input onkeyup=”value=value.replace(/[W]/g,”) ” onbeforepaste=”clipboardData.setData(‘text’,clipboardData.getData(‘text’).replace(/[^d]/g,”))” ID=”Text1″ NAME=”Text1″>
2.只能輸入數(shù)字的： <input onkeyup=”value=value.replace(/[^d]/g,”) ” onbeforepaste=”clipboardData.setData(‘text’,clipboardData.getData(‘text’).replace(/[^d]/g,”))” ID=”Text2″ NAME=”Text2″>
3.只能輸入全角的： <input onkeyup=”value=value.replace(/[^uFF00-uFFFF]/g,”)” onbeforepaste=”clipboardData.setData(‘text’,clipboardData.getData(‘text’).replace(/[^uFF00-uFFFF]/g,”))” ID=”Text3″ NAME=”Text3″>
4.只能輸入漢字的： <input onkeyup=”value=value.replace(/[^u4E00-u9FA5]/g,”)” onbeforepaste=”clipboardData.setData(‘text’,clipboardData.getData(‘text’).replace(/[^u4E00-u9FA5]/g,”))” ID=”Text4″ NAME=”Text4″>
移到輸入框時自動選擇: <input type=”text” id=”text1″ name=”text1″ value=”輸入檢索關鍵字” onclick=”javascript:this.form.text1.focus();this.form.text1.select();” maxlength=”15″ />