How to validate Rich Text in Zoho Creator! Urgent!

How to validate Rich Text in Zoho Creator! Urgent!

Hi members,

Recently I just started to use Rich Text field.

Now I have a requirement where I need to validate to ensure this Rich Text field must contain a value. Meaning must contain something.

I use the below script
if(input.Rich_Text == null)
{
alert "Must fill up a value.";
cancel submit;
}

but this above script worked if the rich text is untouched at all.
When I press the Bold function in the Rich Text field and I did not input any value into this field, and system passed the validation and did not block the user.

Please assist on how to validate to ensure at least something is inputted into the field. Bold, italics, underline are not considered as value.

Thank You