Tach,
<form action="data_select.html" method="get">
<input name="Show_Data" onClick="if(Store.checked=true)
button.Store.disable=false;}"
type="submit" value="SHOW DATA"></input>
</form>
Versuch mal:
<form action="data_select.html" method="get">
<input name="Show_Data" onClick="function enableButton () {if(Store.checked=true) {button.Store.disable=false;}} enableButton();"
type="submit" value="SHOW DATA"></input>
</form>