SWFUpload

hi:

i have a button called button2 in the html page, i didn't set it to the swfu button_placeholder_id.

now i want to click the button to call the selectFile() of swfu.

but failed.it seems nothing happend.

and i try the button1 click event.

but failed again.the document has not button1 element.

can anybody help me?

var swfu;
window.onload = function () {
swfu = new SWFUpload({
// Backend Settings
upload_url: "upload.aspx",
post_params: {
"ASPSESSID": "<%=Session.SessionID %>"
},

// File Upload Settings
file_size_limit: "100 MB",
file_types: "*.PNG",
file_types_description: "PNG Images",
file_upload_limit: "0", // Zero means unlimited

// Event Handler Settings - these functions as defined in Handlers.js
// The handlers are not part of SWFUpload but are part of my website and control how
// my website reacts to the SWFUpload events.
file_queue_error_handler: fileQueueError,
file_dialog_complete_handler: fileDialogComplete,
upload_progress_handler: uploadProgress,
upload_error_handler: uploadError,
upload_success_handler: uploadSuccess,
upload_complete_handler: uploadComplete,

// Button settings
button_image_url: "images/XPButtonUploadText_61x22.png",
button_placeholder_id: "Button1",
button_width: 61,
button_height: 22,
// button_text: '',
// button_text_style: '.button { font-family: Helvetica, Arial, sans-serif; font-size: 14pt; } .buttonSmall { font-size: 10pt; }',
button_text_top_padding: 1,
button_text_left_padding: 5,

// Flash Settings
flash_url: "swfupload/swfupload.swf", // Relative to this file

custom_settings: {
upload_target: "divFileProgressContainer"
},

// Debug Settings
debug: false
});
}
function Button2_onclick() {
swfu.selectFile();
}