The code that replaces all characters except Numbers and commas with js

Replace all characters except Numbers and commas with js

<script language="javascript">  
var str="asdfk,asdf345345,345345"; 
//Replace all characters except Numbers and commas.
str=str.replace(/[^0-9,]*/g,""); 
//Remove the first comma
if (str.substr(0,1)==',') str=str.substr(1);
//Remove the second comma
var reg=/,$/gi; 
str=str.replace(reg,""); 
alert(str); 
</script>

Results:

345345,345345