Prosta Javascript provera, ne radi mi

Code:
<script language="javascript">
         function Proveri(){
     var proizvodjac= document.formular.trazi_pr.value;
     var model= document.formular.trazi_model.value;
     var cena=document.forma.cena.options[document.forma.cena.selectedIndex].value;
             if(proizvodjac=="" && model=="" && cena=="def"){alert("Ukoliko zelite da pretrazite nasu arhivu oglasa, morate uneti bar jedan kriterijum za pretragu");return false;}
            else
            {return true;
                    }
            }                        
</script>

Code:
echo('<form name="formular" method="post" action="result.php" onsubmit="return Proveri();">');
                    echo('<table border="0">
            <tr><td><strong>Proizvodjac:</strong></td><td><input type="text" name="trazi_pr"></td></tr>');
                  echo('<tr><td><strong>Model:</strong></td><td><input type="text" name="trazi_model"</td></tr>');
              echo('<tr><td><strong>Cena:</strong></td><td><select name="cena" id="cena" value="def">
             <option value="def">izaberi</option>
             <option>manje od 5000e</option>
             <option>od 5000e do 7999e</option>
             <option>od 8000e do 10999e</option>
             <option>od 11000e do 13999e</option>
             <option>od 14000e do 16999e</option>
             <option>vece od 17000e</option>
             </select></td></tr>');
                    
echo('<tr><td colspan="2" align="center"><input type="submit" value="Pretraga" name="search" ></td></tr></table>');
echo('</form>');