User form in excel- need help in writing code with if/then statement

frm Inventory - I need to write code when the numeric data entered into txtIssued is >0 then txtReceived be <1 and vice versa. This data needs to be stored into Sheet1. The txtIssued is in column C and the txtReceived is in column D.

Private Sub cmdCANCEL_Click()
    Unload Me
End Sub


Private Sub cmdSAVE_CLICK()
ThisWorkbook.Save 'to save the current workbook

    If Me.txtMaterial = "" Then
    MsgBox "Please enter a Material Number.", vbExclamation, "Inventory"
    Me.txtMaterial.SetFocus
    Exit Sub
    End If
    If Me.txtBin = "" Then
    MsgBox "Please enter a Bin Number.", vbExclamation, "Inventory"
    Me.txtMaterial.SetFocus
    Exit Sub
    End If
    If Me.txtIssued = "" Then
    MsgBox "Please enter Issued Amount.", vbExclamation, "Inventory"
    Me.txtMaterial.SetFocus
    Exit Sub
    End If
    If Me.txtReceived = "" Then
    MsgBox "Please enter Received Amount.", vbExclamation, "Inventory"
    Me.txtMaterial.SetFocus
    Exit Sub
    End If
    If Me.txtDate = "" Then
    MsgBox "Please enter Todays Date.", vbExclamation, "Inventory"
    Me.txtMaterial.SetFocus
    Exit Sub
    End If
      
    If Me.cboDEPARTMENT = "" Then
    MsgBox "Please choose a Department", vbExclamation, "Inventory"
    Me.txtMaterial.SetFocus
    Exit Sub
    End If
    If Me.txtRecipient = "" Then
    MsgBox "Please enter Name of Recipient.", vbExclamation, "Inventory"
    Me.txtMaterial.SetFocus
    Exit Sub
    End If
    If Me.txtFaics = "" Then
    MsgBox "Please enter Faics number.", vbExclamation, "Inventory"
    Me.txtMaterial.SetFocus
    Exit Sub
    End If
    If Me.cboInitials = "" Then
    MsgBox "Please choose your Initials", vbExclamation, "Inventory"
    Me.txtMaterial.SetFocus
    Exit Sub
    End If
    If Not IsNumeric(Me.txtIssued) Then
    MsgBox "The Issued box must contain a number.", vbExclamation, "Inventory"
    Me.txtIssued.SetFocus
    Exit Sub
    End If
    If Not IsDate(Me.txtDate) Then
    MsgBox "The Date box must contain a date.", vbExclamation, "Inventory"
    Me.txtDate.SetFocus
    Exit Sub
    End If
    
    
    
End Sub


Private Sub UserForm_Initialize()
    Me.txtDate = Now
    End Sub