Url rewrite by Web config

<configuration>  
<system.webserver>  
<rewrite>  
   <rules>  
            <rule name="RemoveASPX" enabled="true" stopProcessing="true">  
                <match url="(.*)\.aspx" />  
                <action type="Redirect" url="{R:1}" />  
            rule>  
            <rule name="AddASPX" enabled="true">  
                <match url=".*" negate="false" />  
                <conditions>  
                    <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />  
                    <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />  
                    <add input="{URL}" pattern="(.*)\.(.*)" negate="true" />  
                conditions>  
                <action type="Rewrite" url="{R:0}.aspx" />  
            rule>  
   rules>  
rewrite>  
system.webserver>  
configuration>