This might get you started. You can make the field validation as complex or simple as you wish.
$('input[type=checkbox]').click(function(){
var tmp = $(this).next('input').val();
//validate tmp, for example:
if (tmp.length > 1){
//alert('Text field has a value');
$('#mybutt').prop('disabled',false);
}else{
//alert('Please provide a long value in text field');
$('#mybutt').prop('disabled', true);
$(this).prop('checked',false);
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<input id="mybutt" type="button" value="Add To Calendar" disabled>
<br>
<input type="checkbox" name="dategroup"><input type="text" id="date1">
<br>
<input type="checkbox" name="dategroup"><input type="text" id="date2">
<br>
<input type="checkbox" name="dategroup"><input type="text" id="date3">
1
solved Using jQuery to validate checkboxes and input text values