You need to change name of you function:
<script>
function alert(){
alert(@Html.ValidationSummary(true, "Hatalı giriş. Lütfen tekrar deneyiniz."))
}
</script>
you named you function alert() which is function of alert window in js. So you are making infinite loop for calls. You got stackoverflow :P
use Ctrl+shif+J you can find js errors there