div+css 为什么我给一个div加一个背景图片，如果没加no-repeat 背景图片就有 ，然后就重复，加了图片不显示

no-repeat:就是防止背景图重复
一般的情况要加
div加背景图一般是这样的
backgruound:url(/images/xtjpg) no-repeat;
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要用JS来控制的，单纯的CSS做不到，给你个代码，可以直接拿去用：

<div id="dpro" style="overflow:hidden;width:100%px; padding:10px; margin:0 10px;">
                    <table width="100%" border="0" cellspacing="0" cellpadding="0">
                      <tr>
                        <td id="dpro1">
                        <table width="100%" cellpadding="0" cellspacing="0" border="0">
                            <tr>
                    
<td><div class="index_pic"><a href="product_showaspid=41" title="轻轮"><img src="UploadFiles/20131017164757151png" width="148" height="139" /><span>轻轮</span></a></div></td>
                            
<td><div class="index_pic"><a href="product_showaspid=40" title="轻轮"><img src="UploadFiles/20131017164724200png" width="148" height="139" /><span>轻轮</span></a></div></td>
                            
<td><div class="index_pic"><a href="product_showaspid=39" title="SB-6509-948 "><img src="UploadFiles/2013101716460566png" width="148" height="139" /><span>SB-6509-948&nbsp;</span></a></div></td>
                            
<td><div class="index_pic"><a href="product_showaspid=38" title="CPT-5854-85BRK4 "><img src="UploadFiles/20131017164529355png" width="148" height="139" /><span>CPT-5854-85BRK4&nbsp;…</span></a></div></td>
                            
<td><div class="index_pic"><a href="product_showaspid=37" title="CPT-4856-85BRK4 "><img src="UploadFiles/20131017164455666png" width="148" height="139" /><span>CPT-4856-85BRK4&nbsp;…</span></a></div></td>
                            
<td><div class="index_pic"><a href="product_showaspid=36" title="CPT-5851-85BRK4 "><img src="UploadFiles/20131017164420861png" width="148" height="139" /><span>CPT-5851-85BRK4&nbsp;…</span></a></div></td>
                            
<td><div class="index_pic"><a href="product_showaspid=35" title="医用脚轮"><img src="UploadFiles/20131017164359417png" width="148" height="139" /><span>医用脚轮</span></a></div></td>
                            
<td><div class="index_pic"><a href="product_showaspid=34" title="轻轮"><img src="UploadFiles/20131017164322134jpg" width="148" height="139" /><span>轻轮</span></a></div></td>
                            
<td><div class="index_pic"><a href="product_showaspid=33" title="京华小叶花"><img src="UploadFiles/20139281463567jpg" width="148" height="139" /><span>京华小叶花</span></a></div></td>
                            
                            </tr>
                        </table>
                        </td>
                        <td id="dpro2">&nbsp; </td>
                      </tr>
                    </table>
                    </div>
                    <!-- pro end -->
                    <script language="javascript">
                var ddp = document;
                var dpro = ddpgetElementById("dpro");
                var dpro1 = ddpgetElementById("dpro1");
                var dpro2 = ddpgetElementById("dpro2");
                var dspeed=5; //滚动的速度,数值越大越慢
                dpro2innerHTML=dpro1innerHTML;
                function Marquee()
                {
                    if(dpro2offsetWidth-dproscrollLeft<=0)
                    {
                        dproscrollLeft-=dpro1offsetWidth;
                    }
                    else
                    {
                        dproscrollLeft++;
                    }
                }
                var MyMar=setInterval("Marquee()",dspeed);
                dproonmouseover=function() 
                {
                    clearInterval(MyMar);
                }
                dproonmouseout=function() 
                {
                    MyMar=setInterval("Marquee()",dspeed);
                }
                </script>

no-repeat 这个意思就是背景在这个层里面不横铺也不竖铺，
repeat-x 是背景横向平铺，
repeat-y 是背景图纵向平铺，
你如果加no-repeat没有背景，应该是你的背景图只是一个小，如果不重复铺垫的话估计看不清

关于如何设置 DIV 背景，如下例子：如果是背景重复就把no-repeat改为repeat
div{background:url(images/1jpg) no-repeat;}

html代码:
<div id="pic">
<a href="#"><img src="地址gif"><br></a>
</div>
css代码:
#pic{
width:89px;/的宽度，这里假设的宽度为：89px,/
float:left;
}
记：设浮动的时候要设宽度。

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