function formata(){}

formata.prototype = {
	valor:function(campo,tammax,teclapres,decimal){
		var tecla = teclapres.keyCode;
		vr = this.limparValor(campo.value,"0123456789");
		tam = vr.length;
		dec=decimal
		
		if(tam < tammax && tecla != 8){
			tam = vr.length + 1 ;
		}
		if(tecla == 8){
			tam = tam - 1;
		}
		if(tecla == 8 || tecla >= 48 && tecla <= 57 || tecla >= 96 && tecla <= 105 ){
			if ( tam <= dec ){
				campo.value = vr;
			}
			if((tam > dec) && (tam <= 5)){
				campo.value = vr.substr( 0, tam - 2 ) + "," + vr.substr( tam - dec, tam );
			}
			if((tam >= 6) && (tam <= 8) ){
				campo.value = vr.substr( 0, tam - 5 ) + "." + vr.substr( tam - 5, 3 ) + "," + vr.substr( tam - dec, tam ); 
			}
			if((tam >= 9) && (tam <= 11)){
				campo.value = vr.substr( 0, tam - 8 ) + "." + vr.substr( tam - 8, 3 ) + "." + vr.substr( tam - 5, 3 ) + "," + vr.substr( tam - dec, tam );
			}
				if((tam >= 12) && (tam <= 14)){
					campo.value = vr.substr( 0, tam - 11 ) + "." + vr.substr( tam - 11, 3 ) + "." + vr.substr( tam - 8, 3 ) + "." + vr.substr( tam - 5, 3 ) + "," + vr.substr( tam - dec, tam ) ;
				}
			if((tam >= 15) && (tam <= 17)){
				campo.value = vr.substr( 0, tam - 14 ) + "." + vr.substr( tam - 14, 3 ) + "." + vr.substr( tam - 11, 3 ) + "." + vr.substr( tam - 8, 3 ) + "." + vr.substr( tam - 5, 3 ) + "," + vr.substr( tam - 2, tam );
			}
		} 
	},
	
	limparValor:function(valor, validos)
	{
		var result = "";
		var aux;
		for (var i=0; i < valor.length; i++) {
			aux = validos.indexOf(valor.substring(i, i+1));
			if (aux>=0) {
				result += aux;
			}
		}
	return result;
	}
}

var formata = new formata();


/*
function Limpar(valor, validos) {
// retira caracteres invalidos da string
var result = "";
var aux;
for (var i=0; i < valor.length; i++) {
aux = validos.indexOf(valor.substring(i, i+1));
if (aux>=0) {
result += aux;
}
}
return result;
}
*/