javascriptはurlパラメータを交替します.



<html>  
  <head>  
  <meta   http-equiv="Content-Type"   content="text/html;   charset=gb2312">  
  <title></title>  
<script>  
    function   setUrlParam(oldurl,paramname,pvalue){  
          var   reg   =   new   RegExp("(\\?|&)"+   paramname   +"=([^&]*)(&|$)","gi");  
          var   pst=oldurl.match(reg);  
          if((pst==undefined)   ||   (pst==null)){ 
			return   oldurl+((oldurl.indexOf("?")==-1)?"?":"&")+paramname+"="+pvalue;  
		  }
          var   t=pst[0];  
          var   retxt=t.substring(0,t.indexOf("=")+1)+pvalue;  
          if(t.charAt(t.length-1)=='&')   retxt+="&";  
          return   oldurl.replace(reg,retxt);  
    }  
    alert(setUrlParam("http://servername/virturlpath/index.asp","a4","cxz"));  
	alert(setUrlParam("http://servername/virturlpath/index.asp?p1=123&p2=aa&p3=hh&p4=1","a4","cxz",1));  
	alert(setUrlParam("http://servername/virturlpath/index.asp?a4=abc&p1=123&p2=aa&p3=hh&p4=1","a4","cxz"));  
	alert(setUrlParam("http://servername/virturlpath/index.asp?sa4=abc&p1=123&p2=aa&p3=hh&p4=1","a4","cxz")); 
	alert(setUrlParam("http://servername/virturlpath/index.asp?sa4=abc&p1=123&p2=aa&a4=hh&p4=1","a4","cxz")); 
  </script>    
   
  </head>  
  <body>  
   
  </body>  
  </html>