MoedaMask.js

function MascaraMoeda(objTextBox, SeparadorMilesimo, SeparadorDecimal, e){
    var sep = 0;
    var key = '';
    var i = j = 0;
    var len = len2 = 0;
    var strCheck = '0123456789';
    var aux = aux2 = '';
    var whichCode = (window.Event) ? e.which : e.keyCode;
    if (whichCode == 13) return true;
    key = String.fromCharCode(whichCode); // Valor para o c�digo da Chave
    if (strCheck.indexOf(key) == -1) return false; // Chave inv�lida
    len = objTextBox.value.length;
    for(i = 0; i < len; i++)
        if ((objTextBox.value.charAt(i) != '0') && (objTextBox.value.charAt(i) != SeparadorDecimal)) break;
    aux = '';
    for(; i < len; i++)
        if (strCheck.indexOf(objTextBox.value.charAt(i))!=-1) aux += objTextBox.value.charAt(i);
    aux += key;
    len = aux.length;
    if (len == 0) objTextBox.value = 'R$ ';
    if (len == 1) objTextBox.value = 'R$ '+ SeparadorDecimal + aux;
    if (len == 2) objTextBox.value = 'R$ '+ SeparadorDecimal + aux;
    if (len > 2) {
        aux2 = '';
        for (j = 0, i = len - 3; i >= 0; i--) {
            if (j == 3) {
                aux2 += SeparadorMilesimo;
                j = 0;
            }
            aux2 += aux.charAt(i);
            j++;
        }
        objTextBox.value = 'R$ ';
        len2 = aux2.length;
        console.log(aux2);
        for (i = len2 - 1; i >= 0; i--)
        objTextBox.value += aux2.charAt(i);
        objTextBox.value += SeparadorDecimal + aux.substr(len - 2, len);
    }
    return false;
}

// colocar attrib onkeypress="return(MascaraMoeda(this,'.',',',event))"