function validate(tex)
	{ 
	
	if (tex.length>=3 || tex!="")
		{
		buscador.submit();
		} 	else {alert("La búsqueda por palabra debe tener al menos 3 caracteres.");}
		}

<!-- VALIDA -->

function validamail(email) {
	var is = 0;
	var arroba=0;
	
	    for (var i=1; i<email.length-3; i++){
		var texto=email.substr(i,1);
		if (texto=='@'){
			var arroba=i;
			break
		}

	    }
	    if (arroba>0){
		    for (var i=arroba; i<email.length-1; i++){
			var texto=email.substr(i,1);
			if (texto=='.'){
				var is=1;
				break
			}

		    }
	    }
	    return is;
}

function valida(form) {
ok=1;
    if (!validamail(mailing.email.value)){
	alert('El formato del e-mail es incorecto,\npor favor volve a ingresar tu e-mail...');
	    ok=0;
    }
    if (ok==1) mailing.submit();
}

<!-- VALIDA -->


function selectWin(source,h1,w1)
{ newWin = window.open(source,'','height=' + h1 + ',width=' + w1 + ',top=10,left=10');			}
function selectWin_scroll(source,h1,w1)
{ newWin = window.open(source,'','height=' + h1 + ',width=' + w1 + ',top=10,left=10,scrollbars=yes');			}