Javascript : Finding the Specific Form Field in the Form

for (i = 0; i < document.forms[0].elements.length; i++) {
if (document.forms[0].elements[i].name == 'src_Field1_general') {
document.forms[0].elements["src_Field1_general"].value = '<%=Request.QueryString("src")%>';
}
if (document.forms[0].elements[i].name == 'src_Field2_packs') {
document.forms[0].elements["src_Field2_packs"].value = '<%=Request.QueryString("src")%>';
}
}