copy svg information to form text field about jsignature

[Muiter1]

Solution is moving a part of the code to an JS event.

<script>
    $(document).ready(function() {
        var $sigdiv = $("#signature")

        $sigdiv.jSignature() // inits the jSignature widget.
        // after some doodling...
        $sigdiv.jSignature("reset") // clears the canvas and rerenders the decor on it.
    })
</script>

<script>
function copy()
{
    // signature
    var $sigdiv = $("#signature")
    var datapair = $sigdiv.jSignature("getData", "svgbase64") 
    document.getElementById("signature_svg").value = datapair[1];
}
</script>