function checa() { nform = document.forms[0] if (nform.email.value == "") { alert("Please, insert your email"); nform.email.focus(); nform.email.select(); return false; } else { prim = nform.email.value.indexOf("@") if(prim < 2) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf("@",prim + 1) != -1) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf(".") < 1) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf(" ") != -1) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf("zipmeil.com") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf("hotmeil.com") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf(".@") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf("@.") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf(".com.br.") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf("/") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf("[") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf("]") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf("(") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf(")") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } if(nform.email.value.indexOf("..") > 0) { alert("invalid E-mail format"); nform.email.focus(); nform.email.select(); return false; } } return true; }