Millisecond Forums

Hello,

In my experiment, participants will hear a sound clip with a scream and in the middle of the scream, there will be a control question where a number is played. After the scream trial, participants will be asked a control question and they have to enter the number they heard. At the same time, I will be keeping a tally of the number of coins participants have left. When participants get the number incorrect, I would like them to get notified that they will lose two coins, and I would like their "coins_left" value to subtract two. Is this possible? 

Below is my relevant code

<sound scream1>
/ items = ("one_new.mp3")
/ select = replace
/ erase = false
/ volume = 0
</sound>

<sound scream2>
/ items = ("two_new.mp3")
/ select = replace
/ erase = false
/ volume = 0
</sound>

<sound scream3>
/ items = ("three_new.mp3")
/ select = replace
/ erase = false
/ volume = 0
</sound>

<textbox controlQ1>
/ caption = (controlQ)
/ correctresponse = ("1")
</textbox>

<textbox controlQ1>
/ caption = (controlQ)
/ correctresponse = ("2")
</textbox>

<textbox controlQ3>
/ caption = (controlQ)
/ correctresponse = ("3")
</textbox>


<block waldo1>
/ onblockbegin = [
    values.attempts_left = 3;
    values.circle_x = -10%;
    values.circle_y = -10%;
]
/ timeout = 7000
/ trials = [
    1=clip_first;
]
/ bgstim = (scream1)
</block>

<block waldo2>
/ onblockbegin = [
    values.attempts_left = 3;
    values.circle_x = -10%;
    values.circle_y = -10%;
]
/ timeout = 7000
/ trials = [
    1=clip_first;
]
/ bgstim = (scream2)
</block>

<block waldo3>
/ onblockbegin = [
    values.attempts_left = 3;
    values.circle_x = -10%;
    values.circle_y = -10%;
]
/ timeout = 7000
/ trials = [
    1=clip_first;
]
/ bgstim = (scream3)
</block>

<values coins>
/ coins_left = 130
</values>

<text how_many>
/ items = ("You have <%values.coins_left%> coin(s) left. How many coins do you want to bet?")
/ fontstyle = ("Lucida Grande", 3.11%, true, false, false, false, 5, 0)
/ position = (30,15)
</text>

<surveypage bet>
/ questions = [1=bet_radiobuttons]
/ showpagenumbers = false
/ showquestionnumbers = false
/ stimulustimes = [1=how_many, 1coin, 10coins; 2000=reminder]
/ recorddata = true
/ ontrialend = [
    values.coins_left-=radiobuttons.bet_radiobuttons.response;
]
</surveypage>

expt questionnaires>
/ blocks = [1=waldo1; 2=controlQ1
3=waldo2; 4=controlQ2
5=waldo3; 6=controlQ3]