Código:
Espero puedan ayudarme a solventar este problema, gracias. function validar(); { if(!document.form1.nuevobarco.checked && madeSelectionIMO(IMO,"Please select a ship IMO")){ if(document.form1.nuevobarco.checked && notEmpty(imonuevo, "Please enter the new Ship IMO")) { return true; } } return false; } function madeSelectionIMO(elem, helperMsg){ if(elem.value == "Select IMO..."){ alert(helperMsg); elem.focus(); return false; }else{ return true; } } function notEmpty(elem, helperMsg){ if(elem.value.length == 0){ alert(helperMsg); elem.focus(); // set the focus to this input return false; } return true; }