<input name="start_price" id="start_price" type="text" size="5" onkeyup="value=http://www.mamicode.com/value.replace(/[^/d^/.]/g,‘‘)" onbeforepaste="clipboardData.setData(‘text‘,clipboardData.getData(‘text‘).replace(/[^\d]/g,‘‘))"/>

//只能输入数字  
$("#txtAlladult").keydown(function () {  
    var e = $(this).event || window.event;  
    var code = parseInt(e.keyCode);  
    if (code >= 96 && code <= 105 || code >= 48 && code <= 57 || code == 8) {  
        return true;  
    } else {  
        return false;  
    }  
});