html中设置让div中的内容超出后自动显示滚动条示例分析

<p class="classlist"> 
<p class="autoScroll"> 
<asp:RadioButtonList ID="rblClasses" runat="server" DataTextField="className" DataValueField="classID" 
ForeColor="#FF4040"> 
</asp:RadioButtonList> 
<asp:ImageButton ID="imgSure" runat="server" ImageUrl="~/images/c_sure.jpg" /> 
<asp:ImageButton ID="imgClose" runat="server" ImageUrl="~/images/c_close.jpg" /> 
</p> 
</p>

<style type="text/css"> 
.classlist 
{ 
width: 300px; 
height: 20px; 
} 
.autoScroll 
{ 
width:300px; 
height:100px; 
overflow:auto; 
} 
#rblClasses 
{ 
margin-left: 20px; 
} 
</style>