function isSgNric(oForm, iElementIdx, sElementName) {

//------------------------------------------------------------------
// isSgNric
//
// Ensure Singapore NRIC format of (A1234567A) is entered.
//------------------------------------------------------------------

    var validChar = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
    var validNum = "0123456789";
    var sNric = oForm.elements[iElementIdx].value;
    var sNricMid = sNric.substring(1,7);

    var bCorrect = true;
    var sTemp = "";
    
    	
    for (var i=0; i<7; i++) {
        // validate '1234567'
        sTemp = "" + sNricMid.substring(i, i+1);
        if (validNum.indexOf(sTemp) == "-1") bCorrect = false;
    }
    					
    if ((bCorrect = false) || 
        (validChar.indexOf(sNric.charAt(0)) == "-1") || (validChar.indexOf(sNric.charAt(8)) == "-1")) {
        // validate leading and trailing chars
        alert("Invalid format for " +  sElementName + " field.\n" + "Valid format: A1234567A");
        oForm.elements[iElementIdx].focus();
        return false;
    }
    
    return true;
}