Powershell to press a button in Explorer - powershell

Question

I have a web page with the following code relevant to the button:
<td width=300 align=left>Click here to run the batch tool:</td>
<td align='left' width=100><input id="Submit1" type="submit" value="Run" onClick='showSts();'/></td>
And my attempts to programmatically press it from Powershell using this code:
$username='username' $password='password'
$ie = New-Object -ComObject 'internetExplorer.Application'
$ie.Visible= $true
$ie.Navigate("name of Web site")
while ($ie.Busy -eq $true){Start-Sleep -seconds 1;}
# $usernamefield = $ie.Document.getElementByID('memberemail')
# $usernamefield.value = $username
# $passwordfield = $ie.Document.getElementByID('memberpassword')
# $passwordfield.value = $password
$submitebutton=$ie.Documentelement.getElementByclassname('submit1') | Select-Object -First
$submitebutton.click()
Gives this error:
You cannot call a method on a null-valued expression. At
C:\Users\zkf4bi4\Documents\houdini_click.ps1:15 char:1
+ $submitebutton=$ie.Documentelement.getElementByclassname('submit1') | Select-Ob ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull You cannot call a method on a null-valued expression. At
C:\Users\zkf4bi4\Documents\houdini_click.ps1:16 char:1
+ $submitebutton.click()
+ ~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
Any ideas on how to proceed? I'm an experienced developer but am new to Powershell

Answer 1

Well, I can't help but notice that you're calling GetElementsByClassName but 'Submit1' is the elements id. I suspect the error message is trying to tell you that $submitebutton is null. You might find this question an almost exact duplicate.