Millisecond Forums

I have four groups of images (e.g., A, B, C, D), each group has eight images (currently I put them as text for testing). I want to display two images side by side selected randomly, a text in-between ("Positive" or "Negative" in randomize order) and run trials of equal number of each text.
(Script below)
Questions:
1. Horizontal position:
    How to set horizontal position (/hposition)) values for leftImage and rightImage?
    (Implemented in the script but having issues, sometimes displays horizontal position at zero (as initialized))
2. How to avoid selection of same group on both sides? (e.g., if leftImage comes from group C,
rightImage should be from remaining groups A, B, D but not from group C)
(Tried to branch conditionally but not working - please help)

3. How to avoid selection of same image type on both sides? (e.g., if C5.jpg selected for leftIamge, rightImage can't be A5.jpg, B5.jpg, or D5.jpg, please note I am managing image group by alphabet and type by number)?
(Not sure how to implement)

Would appreciate your kind help.
Thanks

Here is the script in Inquisit-6:
<values>
/ lftimg = ""
/ rgtimg = ""
</values>

<text A>
/items = ("A1.jpg","A2.jpg","A3.jpg","A4.jpg","A5.jpg","A6.jpg","A7.jpg","A8.jpg")
/size = (20%,20%)
/fontstyle = ("Arial", 50pt, true)
/ vposition = 50%
/ hposition = 0%
</text>

<text B>
/items = ("B1.jpg","B2.jpg","B3.jpg","B4.jpg","B5.jpg","B6.jpg","B7.jpg","B8.jpg")
/size = (20%,20%)
/fontstyle = ("Arial", 50pt, true)
/ vposition = 50%
/ hposition = 0%
</text>

<text C>
/items = ("C1.jpg","C2.jpg","C3.jpg","C4.jpg","C5.jpg","C6.jpg","C7.jpg","C8.jpg")
/size = (20%,20%)
/fontstyle = ("Arial", 50pt, true)
/ vposition = 50%
/ hposition = 0%
</text>

<text D>
/items = ("D1.jpg","D2.jpg","D3.jpg","D4.jpg","D5.jpg","D6.jpg","D7.jpg","D8.jpg")
/size = (20%,20%)
/fontstyle = ("Arial", 50pt, true)
/ vposition = 50%
/ hposition = 0%
</text>

<text plus>
/ items = ("Positive")
/ size = (20%, 20%)
/ position = (50%, 50%)
/ fontstyle = ("Arial", 30pt, true)
</text>

<text minus>
/ items = ("Negative")
/ size = (20%, 20%)
/ position = (50%, 50%)
/ fontstyle = ("Arial", 30pt, true)
</text>

<list leftImage>
/ items = (text.A,text.B, text.C, text.D)
/ replace = true
/ selectionrate = always
</list>

<list rightImage>
/ items = (text.A,text.B, text.C, text.D)
/ replace = true
/ selectionrate = always
</list>

<trial plus>
/ ontrialbegin = [trial.plus.insertstimulusframe(list.leftImage.nextvalue, 1);
                 trial.plus.insertstimulusframe(list.rightImage.nextvalue, 1);]
/ branch = [if (substring(list.leftImage.currentvalue, 5, 1) == substring(list.rightImage.currentvalue, 5, 1)) trial.plus]
                
/ ontrialbegin = [if (substring(list.leftImage.currentvalue, 5, 1) == "A") {text.A.hposition = 30%}
                    else if (substring(list.leftImage.currentvalue, 5, 1) == "B") {text.B.hposition = 30%}
                    else if (substring(list.leftImage.currentvalue, 5, 1) == "C") {text.C.hposition = 30%}
                    else if (substring(list.leftImage.currentvalue, 5, 1) == "D") {text.D.hposition = 30%};]

/ ontrialbegin = [if (substring(list.rightImage.currentvalue, 5, 1) == "A") {text.A.hposition = 70%}
                    else if (substring(list.rightImage.currentvalue, 5, 1) == "B") {text.B.hposition = 70%}
                    else if (substring(list.rightImage.currentvalue, 5, 1) == "C") {text.C.hposition = 70%}
                    else if (substring(list.rightImage.currentvalue, 5, 1) == "D") {text.D.hposition = 70%};]

/ stimulusframes = [1=clearScreen; 2=text.plus; 3=list.leftImage, list.rightImage;]
/ validresponse = ("a", "b")
</trial>

<trial minus>
/ ontrialbegin = [trial.minus.insertstimulusframe(list.leftImage.nextvalue, 1);
                 trial.minus.insertstimulusframe(list.rightImage.nextvalue, 1);]
/ branch = [if (substring(list.leftImage.currentvalue, 5, 1) == substring(list.rightImage.currentvalue, 5, 1)) trial.minus]

/ ontrialbegin = [if (substring(list.leftImage.currentvalue, 5, 1) == "A") {text.A.hposition = 30%}
else if (substring(list.leftImage.currentvalue, 5, 1) == "B") {text.B.hposition = 30%}
else if (substring(list.leftImage.currentvalue, 5, 1) == "C") {text.C.hposition = 30%}
else if (substring(list.leftImage.currentvalue, 5, 1) == "D") {text.D.hposition = 30%};]

/ ontrialbegin = [if (substring(list.rightImage.currentvalue, 5, 1) == "A") {text.A.hposition = 70%}
else if (substring(list.rightImage.currentvalue, 5, 1) == "B") {text.B.hposition = 70%}
else if (substring(list.rightImage.currentvalue, 5, 1) == "C") {text.C.hposition = 70%}
else if (substring(list.rightImage.currentvalue, 5, 1) == "D") {text.D.hposition = 70%};]                
                
/ stimulusframes = [1=clearScreen; 2=text.minus; 3=list.leftImage, list.rightImage;]
/ validresponse = ("a", "b")
</trial>

<block tryblock>
/ trials = [1-10=noreplace(plus,minus)]
/ recorddata = true
</block>