CSS Animate SVG Circle Radius

<html>
    <head>
        <link href = "styling.css" rel = "stylesheet" type = "text/css"></link>
    </head>
    <body>
        <svg class = "button" expanded = "true" height = "100px" width = "100px">
            <circle cx = "50%" cy = "50%" r = "35%" stroke = "#000000" stroke-width = "10%" fill = "none"/>
            <circle class = "innerCircle" cx = "50%" cy = "50%" r = "25%" fill = "#000000">
              <animate attributeName="r" begin="0s" dur="1s" repeatCount="indefinite" from="5%" to="25%"/>
            </circle>
        </svg>
    </body>
</html>
Alert Ant