How do I change a widget Property in Code

For instance I want to change a textbox's read only status from within a service.  The text box readonly property doesn't have an input or output on the mashup like some other properties do.  I tried something like this first   

me.textbox-10.ReadOnly=false;

but this failed as the textbox-10 nomenclature caused an error,  which leads me to believe there is some other ID  for textbox-10