在firefox下传文件时获取全路径

  function readFile(fileBrowser) {  
     if (navigator.userAgent.indexOf("MSIE")!=-1) {
    	return  getFilePath(fileBrowser);  
}
     else if (navigator.userAgent.indexOf("Firefox")!=-1|| navigator.userAgent.indexOf("Mozilla")!=-1)    {
        	return getFilePathWithFF(fileBrowser);  
    } else { 
   return;  
      }
   }
     
    
    	     function getFilePath(fileBrowser) {  
    	        if (navigator.userAgent.indexOf("MSIE") != -1){fileBrowser.select(); return document.selection.createRange().text;  }
    	        else if (navigator.userAgent.indexOf("Firefox") != -1 || navigator.userAgent.indexOf("Mozilla") != -1) return this.getFilePathWithFF(fileBrowser);  
    	        else alert("Not IE or Firefox (userAgent=" + navigator.userAgent + ")");  
    	    }; 
    	    function  getFilePathWithFF(fileBrowser) {  
    	        try {  
    	            netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");  
    	        } catch(e) {  
    	            alert('由于浏览器安全问题 请按照以下设置 [1] 地址栏输入 "about:config" ; [2] 右键 新建 -> 布尔值 ; [3] 输入 "signed.applets.codebase_principal_support" (忽略引号).');  
    	            return;  
    	        }  
    	        var fileName = fileBrowser.value;  
    	        var file = Components.classes["@mozilla.org/file/local;1"].createInstance(Components.interfaces.nsILocalFile);  
    	        try {  
    	            // Back slashes for windows  
    	            file.initWithPath(fileName.replace(/\//g, "\\\\"));  
    	        } catch(e) {  
    	            if (e.result != Components.results.NS_ERROR_FILE_UNRECOGNIZED_PATH) throw e;  
    	            alert("File '" + fileName + "' cannot be loaded: relative paths are not allowed. Please provide an absolute path to this file.");  
    	            return;  
    	        }  
    	      
    	        return file.path;  
    	    }