function txtBoxFormat(objForm, strField, sMask, evtKeyPress) {
var i, nCount, sValue, fldLen, mskLen,bolMask, sCod, nTecla;

if(document.all) { // Internet Explorer
    nTecla = evtKeyPress.keyCode;
} else if(document.layers) { // Nestcape
    nTecla = evtKeyPress.which;
} else {
    nTecla = evtKeyPress.which;
    if (nTecla == 8) {
        return true;
    }
}

sValue = objForm[strField].value;
// Limpa todos os caracteres de formatação que
// já estiverem no campo.
sValue = sValue.toString().replace(/\-/g, "");
sValue = sValue.toString().replace(/\./g, "");
sValue = sValue.toString().replace(/\//g, "");
sValue = sValue.toString().replace(/\(/g, "");
sValue = sValue.toString().replace(/\)/g, "");
sValue = sValue.toString().replace(/\s/g, "");
fldLen = sValue.length;
mskLen = sMask.length;

i = 0;
nCount = 0;
sCod = "";
mskLen = fldLen;

while (i <= mskLen) {
bolMask = ((sMask.charAt(i) == "-") || (sMask.charAt(i) == ":") || (sMask.charAt(i) == ".") || (sMask.charAt(i) == "/"))
bolMask = bolMask || ((sMask.charAt(i) == "(") || (sMask.charAt(i) == ")") || (sMask.charAt(i) == " "))

if (bolMask) {
    sCod += sMask.charAt(i);
    mskLen++;
} else {
    sCod += sValue.charAt(nCount);
    nCount++;
}
i++;
}

objForm[strField].value = sCod;
if (nTecla != 8) { // backspace
    if (sMask.charAt(i-1) == "9") { // apenas números...
    return ((nTecla > 47) && (nTecla < 58)); } // números de 0 a 9
else { // qualquer caracter...
    return true;
}
} else {
    return true;
}
}



function Tecla(e)
{
	if (document.all) // Internet Explorer
		var tecla = event.keyCode;
	else if(document.layers) // Nestcape
		var tecla = e.which;
		if (tecla > 47 && tecla < 58) // numeros de 0 a 9
			return true;
		else
			{
				if (tecla != 8) // backspace
					event.keyCode = 0;
					//return false;
				else
					return true;
			}
}