Help with Business Rule on Change Request to Validate Approvers

[Baggies]

On a Change Request form, I have a custom field (reference to sys_user) to add an additional Business Approver.

I want to write a business rule to prevent the Assigned To person from being the same as this Business Approver.

The field name is u_business_approval.

I created a BR, but it will simply not run. After 5 hours of going crazy, I am hoping someone can point me in the right direction.

Business Rue Name: Validate Approvers
Advanced = True
When to run: Before - Update
Order : 100
Condition: (current.state.changesTo(-3) && current.type=='normal') || (current.state.changesTo(-4) && current.type=='normal') 
SCRIPT:

(function executeRule(current, previous /*null when async*/ ) {
    var assignedTo = g_form.getValue("assigned_to");
    if ((assignedTo == g_form.getValue('u_business_approval'))
        // current.setAbortAction(true);

        alert("Business Approver cannot be Assigned To");
        current.state = -5; //check state value
        current.approval = 'not requested'; //remove it if you don't want to set approval
    }
})(current, previous);

Many thanks for any assistance. Mark S.

[Baggies]

Thanks for the replies , after much hairpulling, this is what I ended up with. The main issue I had as making sure the form didnt update the state and approval fields when I hit 'submit for approval'. Any enhancement/ideas for improvement appreciated.

The issue I had was that the state always went to 'Assess', so I had to add code to clear the values.

Would be great if there was a way to reload the form, and set it back to the previous values - ie back tot the state it was before attempting to update the form. Make sense?

Condition: current.state.changesTo(-3)  || current.state.changesTo(-4) ||  current.state.changesTo(-1) ||  current.state.changesTo(-3) || current.state.changesTo(-2)

When to run: Before, Update

(function executeRule(current, previous /*null when async*/ ) {
    var assignedTo = current.assigned_to;

    if ((assignedTo == current.u_business_approval) || (assignedTo == current.u_business_approval_2)) {

        current.setAbortAction(true);

        var message1 = '* Business Approver cannot be Assigned To *';
        var message2 = message1.fontcolor("red");
        gs.addInfoMessage(message2);
        //g_form.clearValue('assigned_to');

        current.state = -5; //check state value
        current.assigned_to = "";
        current.approval = 'not requested'; //remove it if you don't want to set approval
    }
})(current, previous);