Untitled

<!DOCTYPE html>
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

<title>Untitled Document</title>
<script type="text/javascript">
function init() {
    var snabel = document.getElementById("snabel");
    if (snabel !=null) {
        var html = "";
        for (i=1; i<=12; i++) {
            html += '<input type="button" value="-5" onclick="var o=document.getElementById(\'snabel'+i+'\'); o.value = parseInt(o.value) + parseInt(this.value);">';
            html += '<input type="button" value="-3" onclick="var o=document.getElementById(\'snabel'+i+'\'); o.value = parseInt(o.value) + parseInt(this.value);">';
            html += '<input type="button" value="-1" onclick="var o=document.getElementById(\'snabel'+i+'\'); o.value = parseInt(o.value) + parseInt(this.value);">';
            html += '<input name="" type="text" value="0" size="5" id="snabel'+i+'" readonly="true">';
            html += '<input type="button" value="+1" onclick="var o=document.getElementById(\'snabel'+i+'\'); o.value = parseInt(o.value) + parseInt(this.value);">';
            html += '<input type="button" value="+3" onclick="var o=document.getElementById(\'snabel'+i+'\'); o.value = parseInt(o.value) + parseInt(this.value);">';
            html += '<input type="button" value="+5" onclick="var o=document.getElementById(\'snabel'+i+'\'); o.value = parseInt(o.value) + parseInt(this.value);">';
            html += '<br />';

        }
        snabel.innerHTML = html;
    }
}
</script>

</head>

<body onload="init();">
<center id="snabel">
</center>


</body></html>