1.这种相对来说较简单,举例子:
<input name="textfield" type="text" value="点击添入标题" style="color: gray;" onfocus="if (value =='点击添入标题'){value =''}" onblur="if (value ==''){value='点击添入标题'}" />
注:onfocus事件在对象获得焦点时发生;onblur 事件会在对象失去焦点时发生。
2.另外一种复杂一些,用jquery,直接贴代码细看:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>文本框输入值文字消失</title> <script src="js/jquery.js" type="text/javascript"></script> <script type="text/javascript"> $(document).ready(function(){$("#focus .input_txt").each(function(){var thisVal=$(this).val();//判断文本框的值是否为空,有值的情况就隐藏提示语,没有值就显示if(thisVal!=""){$(this).siblings("span").hide();}else{$(this).siblings("span").show();}//聚焦型输入框验证 $(this).focus(function(){$(this).siblings("span").hide();}).blur(function(){var val=$(this).val();if(val!=""){$(this).siblings("span").hide();}else{$(this).siblings("span").show();} });});$("#keydown .input_txt").each(function(){var thisVal=$(this).val();//判断文本框的值是否为空,有值的情况就隐藏提示语,没有值就显示if(thisVal!=""){$(this).siblings("span").hide();}else{$(this).siblings("span").show();}$(this).keyup(function(){var val=$(this).val();$(this).siblings("span").hide();}).blur(function(){var val=$(this).val();if(val!=""){$(this).siblings("span").hide();}else{$(this).siblings("span").show();}})});}); </script> <style type="text/css">form{width:400px;margin:10px auto;border:solid 1px #E0DEDE;background:#FCF9EF;padding:30px;box-shadow:0 1px 10px rgba(0,0,0,0.1) inset;}label{display:block;height:40px;position:relative;margin:20px 0;}span{position:absolute;float:left;line-height:40px;left:10px;color:#BCBCBC;cursor:text;}.input_txt{width:398px;border:solid 1px #ccc;box-shadow:0 1px 10px rgba(0,0,0,0.1) inset;height:38px;text-indent:10px;}.input_txt:focus{box-shadow:0 0 4px rgba(255,153,164,0.8);border:solid 1px #B00000;}.border_radius{border-radius:5px;color:#B00000;}h2{font-family:"微软雅黑";text-shadow:1px 1px 3px #fff;} </style> </head> <body> <form class="border_radius" id="focus"><h2>聚焦型提示语消失</h2><label><span>花瓣注册邮箱</span><input type="text" class="input_txt border_radius" /></label><label><span>密码</span><input type="text" class="input_txt border_radius" /></label></form><form class="border_radius" id="keydown"><h2>输入型提示语消失</h2><label><span>花瓣注册邮箱</span><input type="text" class="input_txt border_radius" /></label><label><span>密码</span><input type="text" class="input_txt border_radius" /></label> </form> </body> </html>