function checkInput() {
    var file = document.getElementById("sfile");
    var seq = document.getElementById("sfield");

    if (file.value == "" && seq.value == "") {
      var error = document.getElementById("error");
      error.style.display = "block";
      //alert("Please insert a sequence or choose an upload file!");
      file.focus();
      return false;
    }          
  }


	function addExample(){
		var seq = document.getElementById("sfield");
  	seq.value=">HTL2\n"+
"LDTAPCLFSDGSPQKAAYVLWDQTILQQDITPLPSHETHSAQKGELLALICGLRAAKPWP\n"+
"SLNIFLDSKYLIKYLHSLAIGAFLGTSAHQTLQAALPPLLQGKTIYLHHVRSHTNLPDPI\n"+
"STFNEYTDSLILAPL\n"+
">MMLV\n"+
"PDADHTWYTDGSSLLQEGQRKAGAAVTTETEVIWAKALDAGTSAQRAELIALTQALKMAE\n"+
"GKKLNVYTDSRYAFATAHIHGEIYRRRGLLTSEGKEIKNKDEILALLKALFLPKRLSIIH\n"+
"CPGHQKGHSAEARGNRMADQAARKAAITETPDTSTLL\n"+
">HEPB\n"+
"RPGLCQVFADATPTGWGLVMGHQRMRGTFSAPLPIHTAELLAACFARSRSGANIIGTDNS\n"+
"VVLSRKYTSFPWLLGCAANWILRGTSFVYVPSALNPADDPSRGRLGLSRPLLRLPFRPTT\n"+
"GRTSLYADSPSVPSHLPDRVH\n"+
">ECOL\n"+
"MLKQVEIFTDGSCLGNPGPGGYGAILRYRGREKTFSAGYTRTTNNRMELMAAIVALEALK\n"+
"EHCEVILSTDSQYVRQGITQWIHNWKKRGWKTADKKPVKNVDLWQRLDAALGQHQIKWEW\n"+
"VKGHAGHPENERCDELARAAAMNPTLEDTGYQVEV\n"
	}