请问我的这个错在哪里(一个JS改变字体颜色)
<head>  <title> 变颜色字体 </title>  
  <script   language= "javascript ">  
 function   bcolor() 
 { 
 var   a=document.yuan.color1.color; 
 if(a!= "red ") 
 a= "red "; 
 } 
  </script>  
  </head>  
  <body>  
  <form   name= "yuan ">  
  <id= "color1 "> 袁浩琳 
  <input   type= "button "   value= "单击 "   onclick= "bcolor() ">    
  </form>
------解决方案-------------------- <head>  <title> 变颜色字体 </title>  
  <script language= "javascript ">  
 function bcolor() 
 { 
 var a=document.all.color1; 
 if(a.style.color!= "red ") 
 	a.style.color= "red "; 
 } 
  </script>  
  </head>  
  <body>  
  <form name= "yuan ">  
  <span id= "color1 "> 袁浩琳 </span>  
  <input type= "button " value= "单击 " onclick= "bcolor() ">    
  </form>