Du kan finde et relativt omfattende eksempel i denne tråd:
http://www.eksperten.dk/spm/524316-- ellers kan du se hvordan det skal fungere med en simplere form her:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "
http://www.w3.org/TR/html4/loose.dtd"><html>
<head>
<title>Check felter for udfyldelse med een advarsel</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script language="javascript" type="text/javascript">
function checkForm(f){
var txt = "",fjl = null,fld;
fld = f.test1;
if(fld.value == "" || fld.value == fld.defaultValue){
txt += "\n\t"+ fld.name + " skal udfyldes";
if(!fjl)fjl = fld;
}
/*Speciel test for f.eks. tal: */
if(!fld.value.match(/^\d+$/)){
txt += "\n\t"+ fld.name + " må kun indeholde tal";
if(!fjl)fjl = fld;
}
fld = f.test2;
if(fld.value == "" || fld.value == fld.defaultValue){
txt += "\n\t"+ fld.name + " skal udfyldes";
if(!fjl)fjl = fld;
}
if(txt!=""){
txt = "Du mangler at udfylde/har udfyldt forkert i disse felter:\n"+txt+"\n\nAlle felter skal udfyldes";
alert(txt);
fjl.select();
fjl.focus()
return false;
}
return true;
}
</script>
</head>
<body>
<br>
<form id="minForm" name="minForm" action="" method="get" onsubmit="return checkForm(this);">
Input1: <input id="test1" name="test1" type="text" value="Kun tal" onfocus="if(this.value==this.defaultValue)this.value='';" onblur="if(this.value=='')this.value=this.defaultValue;" size="30"><br>
Input2: <input id="test2" name="test2" type="text" value="Skal udfyldes" onfocus="if(this.value==this.defaultValue)this.value='';" onblur="if(this.value=='')this.value=this.defaultValue;" size="30"><br>
<input type="submit" value="Send data">
</form>
</body>
</html>
