Opera 9.02 freeze by JavaScript

Question

this Script cause freeze

.
<input type="button" onClick="onClickHandler();" />
.
function onClickHandler(){
   var form = document.getElementById("form");
   if(form){
     var textarea1 = document.getElementById('textarea1');
     if(textarea1){
       if(textarea1.style.color.match(/170/)){
        textarea1.value = "";
       }else{
        textarea1.style.color = "#fff";
        textarea1.value = Base64.encode(textarea1.value);
       }
     }
     var textarea2 = document.getElementById('textarea2');
     if(textarea2){
       if(textarea2.style.color.match(/170/)){
        textarea2.value = "";
       }else{
        textarea2.style.color = "#fff";
        textarea2.value = Base64.encode(textarea1.value);
       }
     }
     var input1 = document.getElementById('input1');
     if(input1.style.color.match(/170/)){
        input1.value = "";
     }
     form.submit();
     form.setAttribute('id','form_after');
   }

return false;
}

What's wrong?