function CalcKeyCode(aChar) {
            var character = aChar.substring(0,1);
            var code = aChar.charCodeAt(0);
            return code;
}


function checkNumber(val) {
            var strPass = val.value;
            var strLength = strPass.length;
            var lchar = val.value.charAt((strLength) - 1);
            var cCode = CalcKeyCode(lchar);

            /* Check if the keyed in character is a number
            do you want alphabetic UPPERCASE only ?
          or lower case only just check their respective
            codes and replace the 48 and 57 */

            if (cCode < 48 || cCode > 57 ) {
                        var myNumber = val.value.substring(0, (strLength) - 1);
                        val.value = myNumber;
            }
            return false;
}

function isDate(str){
            var re = /^(\d{1,2})[\s\.\/-](\d{1,2})[\s\.\/-](\d{4})$/
            if (!re.test(str)) return false;
            var result = str.match(re);
            var y = (result[3]);
            var m = (result[2]);
            var d = (result[1]);
            //alert("dia= "+d+" mes= "+m+" ano= "+y);
            if(m < 0 || m > 12 || y < 1900 || y > 2100) return false;
            if(m == 2){
                        var days = ((y % 4) == 0) ? 29 : 28;
            }else if(m == 04 || m == 06 || m == 09 || m == 11){
                        var days = 30;
            }else{
                        var days = 31;
            }
            return (d >= 1 && d <= days);
}

function formatar(src, mask) {
            var i = src.value.length;
            var saida = mask.substring(0,1);

            var texto = mask.substring(i)

            if (texto.substring(0,1) != saida) {
                        src.value += texto.substring(0,1);
            }
}
 
function valida(campo) {
	if(campo.value.length>0) {
		if(!isDate(campo.value)) {
			alert("Data informada inválida!\n Por favor verifique.");
			campo.focus();
        	return false;
		}
	}
}