function ValidateInput(checkVal){
        len = checkVal.length;
        for (i = 0; i<len; i++) {
        if (!((checkVal.substring(i, i+1)=="0") ||
                (checkVal.substring(i,i+1)=="1") ||
                (checkVal.substring(i,i+1)=="2") ||
                (checkVal.substring(i,i+1)=="3") ||
                (checkVal.substring(i,i+1)=="4") ||
                (checkVal.substring(i,i+1)=="5") ||
                (checkVal.substring(i,i+1)=="6") ||
                (checkVal.substring(i,i+1)=="7") ||
                (checkVal.substring(i,i+1)=="8") ||
                (checkVal.substring(i,i+1)=="9") ||
                (checkVal.substring(i,i+1)=="."))) {
                errorMsg = "You have entered an invalid number. Please enter a new amount and try again.";
                        return true;
                }
        }
        if (!((checkVal >= 0) & (checkVal < 300))) {
                errorMsg = "Numbers way out of range";
                return true;
        } else {
        return false;
        }
}


function doStuff(form)  {


var rts = 0;
var rr = document.rtscalc.resprate.value;
var sbp = document.rtscalc.sysbp.value;
var gcs = document.rtscalc.coma.value;
var rri = 0;
var sbpi = 0;
var gcsi = 0;


        if (ValidateInput(rr)) {
            window.alert(errorMsg);
                distance = 0;
                }

        if (ValidateInput(sbp)) {
            window.alert(errorMsg);
                distance = 0;
                }

        if (ValidateInput(gcs)) {
            window.alert(errorMsg);
                distance = 0;
                }

		if (gcs == 3) gcsi = 0;
		else if (gcs >= 4 && gcs <= 5) gcsi = 1;
		else if (gcs >= 6 && gcs <= 8) gcsi = 2;
		else if (gcs >= 9 && gcs <= 12) gcsi = 3;
		else if (gcs >= 13 && gcs <= 15) gcsi = 4;
		else alert('Glasgow Coma Score has values 3-15');

		if (rr >= 10 && rr <= 29) rri = 4;
		else if (rr >= 30 && rr <=80) rri = 3;
		else if (rr >= 6 && rr <= 9) rri = 2;
		else if (rr >= 1 && rr <= 5) rri = 1;
		else if (rr == 0) rri = 0;
		else alert('Respiratory rate invalid');

		if (sbp >= 90 && sbp <= 300) sbpi = 4;
		else if (sbp >= 76 && sbp <= 89) sbpi = 3;
		else if (sbp >= 50 && sbp <= 75) sbpi = 2;
		else if (sbp >= 1 && sbp <= 49) sbpi = 1;
		else if (sbp == 0) sbpi = 0;
		else alert('Systolic Blood Pressure Invalid');

		rts = sbpi*0.7326 + rri*0.2908 + gcsi*0.9368;


        document.rtscalc.rtsscore.value = (Math.round(1000 * rts)/1000);
}

function open_window(url) {
mywin = window.open(url,"rtswin",'toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=0,resizable=0,width=180,height=220');
}