How to determine LMS status Complete on the basis of user score (Custom Scoring)

I have used the custom score variable and wanted to set LMS status as complete on the basis of the user score. However, the completion status is being determined based on slides viewed. For example, If I have scored below 75% and attempted all the questions, the LMS status should be incomplete and failed, but it is reflecting as complete.

I have used following js code on the last screen:

var player=GetPlayer();
var cScore=player.GetVar("FinalScore");

var lmsAPI = parent;
lmsAPI.SetScore(cScore, 100, 0);

if (cScore>=75)
{
SetStatus("completed");
}
else
{
SetStatus("incomplete");
}

Please help me to sort out this problem ASAP as an important project delivery of mine depends on this.