change style of selected word using Paragraph style sheet in Quark 6.5

Hi,

I want to change the style and shade of the word “behavior” of all paragraphs that have the style sheet “READ_MID” to italic and 50%.

Below is the script I used to change the style. But It shows the error when I run the script.

tell application "QuarkXPress"
	repeat with i from 1 to count of text box of document 1
		set properties of (every word of story 1 of text box i of document 1 whose (contents is "behavior" and name of style sheet is "READ_MID")) to {style:italic, shade:"50%"}
	end repeat
end tell

Please help me on this.

Thanks,
Krishnan

Can I get any help on this.