function checkNum(zone, min, max) {
	var C_Num = zone.value;
	var N_Num = 0;

	if(isNaN(C_Num)) {
		zone.value = "";
		zone.focus();
	 	return;
 	}

	N_Num = parseInt(C_Num, 10);  

	if((N_Num < parseInt(min, 10)) || (N_Num > parseInt(max, 10))) {
		zone.value = "";
		zone.focus();
	 	return;
	}

	return;
}

function checkNumber(zone, message) {
	var C_Num = zone.value;
	if(isNaN(C_Num)) {
		window.alert(message);
		zone.value = "";
		zone.focus();
	 	return;
 	}
	return;
}

function checkNumber(zone, min, max, message1, message2) {
	var C_Num = zone.value;
	var N_Num = 0;

	if(isNaN(C_Num)) {
		window.alert(message1);
		zone.value = "";
		zone.focus();
	 	return;
 	}

	N_Num = parseInt(C_Num, 10);  

	if((N_Num < parseInt(min, 10)) || (N_Num > parseInt(max, 10))) {
		window.alert(message2);
		zone.value = "";
		zone.focus();
	 	return;
	}

	return;
}

function checkDate(zone, message) {
	C_Date = zone.value;

	if(C_Date == "")
		return;

	var D_date = new Date(parseInt("" + C_Date.charAt(6) + C_Date.charAt(7) + C_Date.charAt(8) + C_Date.charAt(9), 10),
							(parseInt("" + C_Date.charAt(3) + C_Date.charAt(4), 10) - 1),
							parseInt("" + C_Date.charAt(0) + C_Date.charAt(1), 10));

	if( (D_date.getFullYear() != parseInt("" + C_Date.charAt(6) + C_Date.charAt(7) + C_Date.charAt(8) + C_Date.charAt(9), 10)) 
		|| ((D_date.getMonth() + 1) != parseInt("" + C_Date.charAt(3) + C_Date.charAt(4), 10))
		|| (D_date.getDate() != parseInt("" + C_Date.charAt(0) + C_Date.charAt(1), 10)) ) {
   		window.alert(message);
		zone.value = "";
		zone.focus();
		return;
	}
}

function checkDate(date) {
	C_Date = date;

	if(C_Date == "")
		return false;

	var D_date = new Date(parseInt("" + C_Date.charAt(6) + C_Date.charAt(7) + C_Date.charAt(8) + C_Date.charAt(9), 10),
							(parseInt("" + C_Date.charAt(3) + C_Date.charAt(4), 10) - 1),
							parseInt("" + C_Date.charAt(0) + C_Date.charAt(1), 10));

	if( (D_date.getFullYear() != parseInt("" + C_Date.charAt(6) + C_Date.charAt(7) + C_Date.charAt(8) + C_Date.charAt(9), 10)) 
		|| ((D_date.getMonth() + 1) != parseInt("" + C_Date.charAt(3) + C_Date.charAt(4), 10))
		|| (D_date.getDate() != parseInt("" + C_Date.charAt(0) + C_Date.charAt(1), 10)) ) {
		return false;
	}
	
	return true;
}

function checkNRN(nrn) {
	var nr=nrn;
	var z1=nr%100;
	var z2=nr-z1;
	var z3=z2/100;
	var z4=z3%97;
	var z5=97-z4;
	if(z1==z5) {
		return true;
	} else {
		var z6=z3+2000000000;
		var z10=z6%97;
		var z11=97-z10;

		if(z1==z11) {
			return true;
		} else {
			return false;
		}
	}
}

function tab(zone, nextzone, size) {
	if(zone.value.length == size) {
		nextzone.focus();

	}
}

function trim(chaine) {
 var taille = 0;
 var cx = 0;
 var temp = "";

 taille = chaine.length;
 
 for(cx = 0 ; cx < taille ; cx++) {
 	if(chaine.charAt(cx) != ' ')
		temp = temp + chaine.charAt(cx);
 }

 return temp;
}

function checkCpt(cpt) {
 var taille = 0;

 cpt = trim(cpt);
 taille = cpt.length;

 if(taille != 12)
 	return false;

 // check modulo...
 if(isNaN(cpt) == false) {
 	var z1=cpt%100;
    var z2=cpt-z1;
    var z3=z2/100;
    var z4=z3%97;

    if(z4 == 0)
		z4=97;

    if(z1 != z4)
		return false;
 } else {
	return false;
 }
 
 return true;
}