I made one assuming you have multiple passwords stored
passtest$=prompt()
until(found!)
{
 local(x!,0)
 //added "!found!" jic you had multiple if statements
 if(passvar[x!]$ == passtest$ && !found!)
 {
 //do success stuff here
 found!=1 //or you can have found!++
 }
 x!++
}
There may need to be some tweaking but the gist is there.