In the process of developing a form to be used in a browser I needed to replicate the computed when composed funtion in a client. Chris Toohey informed me of the readonly HTML tag which does exactly what I needed. However, the default look of a readonly field is a grey background with a border. I wanted to have a white background with no border.
I solved this by creating the below CSS in the HTML Head Content:
.ro {
width: 100%;
background-color:#FFFFFF;
color:#222;
border:none;
}
Once I had this I went to the HTML tab of the field and added the ro to the Class field and readonly to the Other field.
Problem solved