the below function is not working in IE version

the below function is not working in IE version

function chooseFreqMenu(freqValues,freqTexts) { var cf = document.myform;
alert(freq1);// displaying freq1 value is "d" (ex:selected 'd' in html
dropdown)
// checking some condition for freqValues.
for(var i=4;i<freqValues.length;i++)
selectStr += '<option value="'+freqValues[i]+'">'+freqTexts[i]+'\n';
}
selectStr += '</select>';
//Its working fine in IE=10 browsers but not in less
document.getElementById("freq").innerHTML= selectStr;