如何将实体直线改成透明直线

<HTML xmlns:v> 
<HEAD> 
<title>WebForm5</title> 
<meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1"> 
<meta name="CODE_LANGUAGE" Content="C#"> 
<meta name="vs_defaultClientScript" content="JavaScript"> 
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5"> 
<style> v\:* { BEHAVIOR: url(#default#VML) } </style> 
</HEAD> 
<body MS_POSITIONING="GridLayout"> 
 
<v:line style="POSITION:absolute" strokecolor='#ceceff' StrokeWeight='7pt' from='150pt,75pt' 
to='375pt,75pt'> 
<v:shadow on="t" type="single" color="#b3b3b3" offset="1.5pt,1.5pt" /> 
<v:Stroke Endarrow='classic' /> 
</v:line></body> 
</HTML> 以上是一条实体直线，如何将它改成透明的直线，需要增加什么样式啊？？？